ETH Price: $2,126.18 (-0.70%)

Transaction Decoder

Block:
13207233 at Sep-11-2021 10:48:09 PM +UTC
Transaction Fee:
0.005543525 ETH $11.79
Gas Used:
149,825 Gas / 37 Gwei

Emitted Events:

407 Strong.Transfer( from=[Sender] 0x0e8891aa4c4576ff7d5577b22c2b54151012d50c, to=0x4B5057B2c87Ec9e7C047fb00c0E406dfF2FDaCad, value=10000000000000000000 )
408 Strong.Approval( owner=[Sender] 0x0e8891aa4c4576ff7d5577b22c2b54151012d50c, spender=[Receiver] TransparentUpgradeableProxy, value=115792089237316195423570985008687907853269984665640564039447584007913129639935 )
409 TransparentUpgradeableProxy.0xd8722907e22bdf7371f82757663f42769580522cf1fc9af2c0740ac3135e9d50( 0xd8722907e22bdf7371f82757663f42769580522cf1fc9af2c0740ac3135e9d50, 0x0000000000000000000000000e8891aa4c4576ff7d5577b22c2b54151012d50c, 0000000000000000000000000000000000000000000000000000000000000001, 0000000000000000000000000000000000000000000000000000000000000000, 0000000000000000000000000000000000000000000000000000000000cc8c61 )

Account State Difference:

  Address   Before After State Difference Code
0x0E8891aA...51012d50C
0.027227887919694033 Eth
Nonce: 16
0.014684362919694033 Eth
Nonce: 17
0.012543525
0x4B5057B2...fF2FDaCad 68.721942871676728527 Eth68.728942871676728527 Eth0.007
0x990f3419...87168017c
(Ethermine)
2,668.695007180208105794 Eth2,668.695242397325305144 Eth0.00023521711719935
0xF9D98634...b8EECf578

Execution Trace

ETH 0.007 TransparentUpgradeableProxy.CALL( )
  • ETH 0.007 NodesV1.DELEGATECALL( )
    • ETH 0.007 0x4b5057b2c87ec9e7c047fb00c0e406dff2fdacad.CALL( )
    • Strong.transferFrom( sender=0x0E8891aA4C4576fF7d5577B22c2b54151012d50C, recipient=0x4B5057B2c87Ec9e7C047fb00c0E406dfF2FDaCad, amount=10000000000000000000 ) => ( True )
      File 1 of 3: TransparentUpgradeableProxy
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      import "@openzeppelin/contracts/proxy/ERC1967/ERC1967Proxy.sol";
      import "@openzeppelin/contracts/proxy/transparent/TransparentUpgradeableProxy.sol";
      import "@openzeppelin/contracts/proxy/transparent/ProxyAdmin.sol";
      // Kept for backwards compatibility with older versions of Hardhat and Truffle plugins.
      contract AdminUpgradeabilityProxy is TransparentUpgradeableProxy {
          constructor(address logic, address admin, bytes memory data) payable TransparentUpgradeableProxy(logic, admin, data) {}
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      import "../Proxy.sol";
      import "./ERC1967Upgrade.sol";
      /**
       * @dev This contract implements an upgradeable proxy. It is upgradeable because calls are delegated to an
       * implementation address that can be changed. This address is stored in storage in the location specified by
       * https://eips.ethereum.org/EIPS/eip-1967[EIP1967], so that it doesn't conflict with the storage layout of the
       * implementation behind the proxy.
       */
      contract ERC1967Proxy is Proxy, ERC1967Upgrade {
          /**
           * @dev Initializes the upgradeable proxy with an initial implementation specified by `_logic`.
           *
           * If `_data` is nonempty, it's used as data in a delegate call to `_logic`. This will typically be an encoded
           * function call, and allows initializating the storage of the proxy like a Solidity constructor.
           */
          constructor(address _logic, bytes memory _data) payable {
              assert(_IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1));
              _upgradeToAndCall(_logic, _data, false);
          }
          /**
           * @dev Returns the current implementation address.
           */
          function _implementation() internal view virtual override returns (address impl) {
              return ERC1967Upgrade._getImplementation();
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      import "../ERC1967/ERC1967Proxy.sol";
      /**
       * @dev This contract implements a proxy that is upgradeable by an admin.
       *
       * To avoid https://medium.com/nomic-labs-blog/malicious-backdoors-in-ethereum-proxies-62629adf3357[proxy selector
       * clashing], which can potentially be used in an attack, this contract uses the
       * https://blog.openzeppelin.com/the-transparent-proxy-pattern/[transparent proxy pattern]. This pattern implies two
       * things that go hand in hand:
       *
       * 1. If any account other than the admin calls the proxy, the call will be forwarded to the implementation, even if
       * that call matches one of the admin functions exposed by the proxy itself.
       * 2. If the admin calls the proxy, it can access the admin functions, but its calls will never be forwarded to the
       * implementation. If the admin tries to call a function on the implementation it will fail with an error that says
       * "admin cannot fallback to proxy target".
       *
       * These properties mean that the admin account can only be used for admin actions like upgrading the proxy or changing
       * the admin, so it's best if it's a dedicated account that is not used for anything else. This will avoid headaches due
       * to sudden errors when trying to call a function from the proxy implementation.
       *
       * Our recommendation is for the dedicated account to be an instance of the {ProxyAdmin} contract. If set up this way,
       * you should think of the `ProxyAdmin` instance as the real administrative interface of your proxy.
       */
      contract TransparentUpgradeableProxy is ERC1967Proxy {
          /**
           * @dev Initializes an upgradeable proxy managed by `_admin`, backed by the implementation at `_logic`, and
           * optionally initialized with `_data` as explained in {ERC1967Proxy-constructor}.
           */
          constructor(address _logic, address admin_, bytes memory _data) payable ERC1967Proxy(_logic, _data) {
              assert(_ADMIN_SLOT == bytes32(uint256(keccak256("eip1967.proxy.admin")) - 1));
              _changeAdmin(admin_);
          }
          /**
           * @dev Modifier used internally that will delegate the call to the implementation unless the sender is the admin.
           */
          modifier ifAdmin() {
              if (msg.sender == _getAdmin()) {
                  _;
              } else {
                  _fallback();
              }
          }
          /**
           * @dev Returns the current admin.
           *
           * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyAdmin}.
           *
           * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
           * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
           * `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103`
           */
          function admin() external ifAdmin returns (address admin_) {
              admin_ = _getAdmin();
          }
          /**
           * @dev Returns the current implementation.
           *
           * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyImplementation}.
           *
           * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
           * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
           * `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc`
           */
          function implementation() external ifAdmin returns (address implementation_) {
              implementation_ = _implementation();
          }
          /**
           * @dev Changes the admin of the proxy.
           *
           * Emits an {AdminChanged} event.
           *
           * NOTE: Only the admin can call this function. See {ProxyAdmin-changeProxyAdmin}.
           */
          function changeAdmin(address newAdmin) external virtual ifAdmin {
              _changeAdmin(newAdmin);
          }
          /**
           * @dev Upgrade the implementation of the proxy.
           *
           * NOTE: Only the admin can call this function. See {ProxyAdmin-upgrade}.
           */
          function upgradeTo(address newImplementation) external ifAdmin {
              _upgradeToAndCall(newImplementation, bytes(""), false);
          }
          /**
           * @dev Upgrade the implementation of the proxy, and then call a function from the new implementation as specified
           * by `data`, which should be an encoded function call. This is useful to initialize new storage variables in the
           * proxied contract.
           *
           * NOTE: Only the admin can call this function. See {ProxyAdmin-upgradeAndCall}.
           */
          function upgradeToAndCall(address newImplementation, bytes calldata data) external payable ifAdmin {
              _upgradeToAndCall(newImplementation, data, true);
          }
          /**
           * @dev Returns the current admin.
           */
          function _admin() internal view virtual returns (address) {
              return _getAdmin();
          }
          /**
           * @dev Makes sure the admin cannot access the fallback function. See {Proxy-_beforeFallback}.
           */
          function _beforeFallback() internal virtual override {
              require(msg.sender != _getAdmin(), "TransparentUpgradeableProxy: admin cannot fallback to proxy target");
              super._beforeFallback();
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      import "./TransparentUpgradeableProxy.sol";
      import "../../access/Ownable.sol";
      /**
       * @dev This is an auxiliary contract meant to be assigned as the admin of a {TransparentUpgradeableProxy}. For an
       * explanation of why you would want to use this see the documentation for {TransparentUpgradeableProxy}.
       */
      contract ProxyAdmin is Ownable {
          /**
           * @dev Returns the current implementation of `proxy`.
           *
           * Requirements:
           *
           * - This contract must be the admin of `proxy`.
           */
          function getProxyImplementation(TransparentUpgradeableProxy proxy) public view virtual returns (address) {
              // We need to manually run the static call since the getter cannot be flagged as view
              // bytes4(keccak256("implementation()")) == 0x5c60da1b
              (bool success, bytes memory returndata) = address(proxy).staticcall(hex"5c60da1b");
              require(success);
              return abi.decode(returndata, (address));
          }
          /**
           * @dev Returns the current admin of `proxy`.
           *
           * Requirements:
           *
           * - This contract must be the admin of `proxy`.
           */
          function getProxyAdmin(TransparentUpgradeableProxy proxy) public view virtual returns (address) {
              // We need to manually run the static call since the getter cannot be flagged as view
              // bytes4(keccak256("admin()")) == 0xf851a440
              (bool success, bytes memory returndata) = address(proxy).staticcall(hex"f851a440");
              require(success);
              return abi.decode(returndata, (address));
          }
          /**
           * @dev Changes the admin of `proxy` to `newAdmin`.
           *
           * Requirements:
           *
           * - This contract must be the current admin of `proxy`.
           */
          function changeProxyAdmin(TransparentUpgradeableProxy proxy, address newAdmin) public virtual onlyOwner {
              proxy.changeAdmin(newAdmin);
          }
          /**
           * @dev Upgrades `proxy` to `implementation`. See {TransparentUpgradeableProxy-upgradeTo}.
           *
           * Requirements:
           *
           * - This contract must be the admin of `proxy`.
           */
          function upgrade(TransparentUpgradeableProxy proxy, address implementation) public virtual onlyOwner {
              proxy.upgradeTo(implementation);
          }
          /**
           * @dev Upgrades `proxy` to `implementation` and calls a function on the new implementation. See
           * {TransparentUpgradeableProxy-upgradeToAndCall}.
           *
           * Requirements:
           *
           * - This contract must be the admin of `proxy`.
           */
          function upgradeAndCall(TransparentUpgradeableProxy proxy, address implementation, bytes memory data) public payable virtual onlyOwner {
              proxy.upgradeToAndCall{value: msg.value}(implementation, data);
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      /**
       * @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM
       * instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to
       * be specified by overriding the virtual {_implementation} function.
       *
       * Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a
       * different contract through the {_delegate} function.
       *
       * The success and return data of the delegated call will be returned back to the caller of the proxy.
       */
      abstract contract Proxy {
          /**
           * @dev Delegates the current call to `implementation`.
           *
           * This function does not return to its internall call site, it will return directly to the external caller.
           */
          function _delegate(address implementation) internal virtual {
              // solhint-disable-next-line no-inline-assembly
              assembly {
                  // Copy msg.data. We take full control of memory in this inline assembly
                  // block because it will not return to Solidity code. We overwrite the
                  // Solidity scratch pad at memory position 0.
                  calldatacopy(0, 0, calldatasize())
                  // Call the implementation.
                  // out and outsize are 0 because we don't know the size yet.
                  let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)
                  // Copy the returned data.
                  returndatacopy(0, 0, returndatasize())
                  switch result
                  // delegatecall returns 0 on error.
                  case 0 { revert(0, returndatasize()) }
                  default { return(0, returndatasize()) }
              }
          }
          /**
           * @dev This is a virtual function that should be overriden so it returns the address to which the fallback function
           * and {_fallback} should delegate.
           */
          function _implementation() internal view virtual returns (address);
          /**
           * @dev Delegates the current call to the address returned by `_implementation()`.
           *
           * This function does not return to its internall call site, it will return directly to the external caller.
           */
          function _fallback() internal virtual {
              _beforeFallback();
              _delegate(_implementation());
          }
          /**
           * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other
           * function in the contract matches the call data.
           */
          fallback () external payable virtual {
              _fallback();
          }
          /**
           * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
           * is empty.
           */
          receive () external payable virtual {
              _fallback();
          }
          /**
           * @dev Hook that is called before falling back to the implementation. Can happen as part of a manual `_fallback`
           * call, or as part of the Solidity `fallback` or `receive` functions.
           *
           * If overriden should call `super._beforeFallback()`.
           */
          function _beforeFallback() internal virtual {
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.2;
      import "../beacon/IBeacon.sol";
      import "../../utils/Address.sol";
      import "../../utils/StorageSlot.sol";
      /**
       * @dev This abstract contract provides getters and event emitting update functions for
       * https://eips.ethereum.org/EIPS/eip-1967[EIP1967] slots.
       *
       * _Available since v4.1._
       *
       * @custom:oz-upgrades-unsafe-allow delegatecall
       */
      abstract contract ERC1967Upgrade {
          // This is the keccak-256 hash of "eip1967.proxy.rollback" subtracted by 1
          bytes32 private constant _ROLLBACK_SLOT = 0x4910fdfa16fed3260ed0e7147f7cc6da11a60208b5b9406d12a635614ffd9143;
          /**
           * @dev Storage slot with the address of the current implementation.
           * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
           * validated in the constructor.
           */
          bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
          /**
           * @dev Emitted when the implementation is upgraded.
           */
          event Upgraded(address indexed implementation);
          /**
           * @dev Returns the current implementation address.
           */
          function _getImplementation() internal view returns (address) {
              return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
          }
          /**
           * @dev Stores a new address in the EIP1967 implementation slot.
           */
          function _setImplementation(address newImplementation) private {
              require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
              StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
          }
          /**
           * @dev Perform implementation upgrade
           *
           * Emits an {Upgraded} event.
           */
          function _upgradeTo(address newImplementation) internal {
              _setImplementation(newImplementation);
              emit Upgraded(newImplementation);
          }
          /**
           * @dev Perform implementation upgrade with additional setup call.
           *
           * Emits an {Upgraded} event.
           */
          function _upgradeToAndCall(address newImplementation, bytes memory data, bool forceCall) internal {
              _setImplementation(newImplementation);
              emit Upgraded(newImplementation);
              if (data.length > 0 || forceCall) {
                  Address.functionDelegateCall(newImplementation, data);
              }
          }
          /**
           * @dev Perform implementation upgrade with security checks for UUPS proxies, and additional setup call.
           *
           * Emits an {Upgraded} event.
           */
          function _upgradeToAndCallSecure(address newImplementation, bytes memory data, bool forceCall) internal {
              address oldImplementation = _getImplementation();
              // Initial upgrade and setup call
              _setImplementation(newImplementation);
              if (data.length > 0 || forceCall) {
                  Address.functionDelegateCall(newImplementation, data);
              }
              // Perform rollback test if not already in progress
              StorageSlot.BooleanSlot storage rollbackTesting = StorageSlot.getBooleanSlot(_ROLLBACK_SLOT);
              if (!rollbackTesting.value) {
                  // Trigger rollback using upgradeTo from the new implementation
                  rollbackTesting.value = true;
                  Address.functionDelegateCall(
                      newImplementation,
                      abi.encodeWithSignature(
                          "upgradeTo(address)",
                          oldImplementation
                      )
                  );
                  rollbackTesting.value = false;
                  // Check rollback was effective
                  require(oldImplementation == _getImplementation(), "ERC1967Upgrade: upgrade breaks further upgrades");
                  // Finally reset to the new implementation and log the upgrade
                  _setImplementation(newImplementation);
                  emit Upgraded(newImplementation);
              }
          }
          /**
           * @dev Perform beacon upgrade with additional setup call. Note: This upgrades the address of the beacon, it does
           * not upgrade the implementation contained in the beacon (see {UpgradeableBeacon-_setImplementation} for that).
           *
           * Emits a {BeaconUpgraded} event.
           */
          function _upgradeBeaconToAndCall(address newBeacon, bytes memory data, bool forceCall) internal {
              _setBeacon(newBeacon);
              emit BeaconUpgraded(newBeacon);
              if (data.length > 0 || forceCall) {
                  Address.functionDelegateCall(IBeacon(newBeacon).implementation(), data);
              }
          }
          /**
           * @dev Storage slot with the admin of the contract.
           * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
           * validated in the constructor.
           */
          bytes32 internal constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
          /**
           * @dev Emitted when the admin account has changed.
           */
          event AdminChanged(address previousAdmin, address newAdmin);
          /**
           * @dev Returns the current admin.
           */
          function _getAdmin() internal view returns (address) {
              return StorageSlot.getAddressSlot(_ADMIN_SLOT).value;
          }
          /**
           * @dev Stores a new address in the EIP1967 admin slot.
           */
          function _setAdmin(address newAdmin) private {
              require(newAdmin != address(0), "ERC1967: new admin is the zero address");
              StorageSlot.getAddressSlot(_ADMIN_SLOT).value = newAdmin;
          }
          /**
           * @dev Changes the admin of the proxy.
           *
           * Emits an {AdminChanged} event.
           */
          function _changeAdmin(address newAdmin) internal {
              emit AdminChanged(_getAdmin(), newAdmin);
              _setAdmin(newAdmin);
          }
          /**
           * @dev The storage slot of the UpgradeableBeacon contract which defines the implementation for this proxy.
           * This is bytes32(uint256(keccak256('eip1967.proxy.beacon')) - 1)) and is validated in the constructor.
           */
          bytes32 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;
          /**
           * @dev Emitted when the beacon is upgraded.
           */
          event BeaconUpgraded(address indexed beacon);
          /**
           * @dev Returns the current beacon.
           */
          function _getBeacon() internal view returns (address) {
              return StorageSlot.getAddressSlot(_BEACON_SLOT).value;
          }
          /**
           * @dev Stores a new beacon in the EIP1967 beacon slot.
           */
          function _setBeacon(address newBeacon) private {
              require(
                  Address.isContract(newBeacon),
                  "ERC1967: new beacon is not a contract"
              );
              require(
                  Address.isContract(IBeacon(newBeacon).implementation()),
                  "ERC1967: beacon implementation is not a contract"
              );
              StorageSlot.getAddressSlot(_BEACON_SLOT).value = newBeacon;
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      /**
       * @dev This is the interface that {BeaconProxy} expects of its beacon.
       */
      interface IBeacon {
          /**
           * @dev Must return an address that can be used as a delegate call target.
           *
           * {BeaconProxy} will check that this address is a contract.
           */
          function implementation() external view returns (address);
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      /**
       * @dev Collection of functions related to the address type
       */
      library Address {
          /**
           * @dev Returns true if `account` is a contract.
           *
           * [IMPORTANT]
           * ====
           * It is unsafe to assume that an address for which this function returns
           * false is an externally-owned account (EOA) and not a contract.
           *
           * Among others, `isContract` will return false for the following
           * types of addresses:
           *
           *  - an externally-owned account
           *  - a contract in construction
           *  - an address where a contract will be created
           *  - an address where a contract lived, but was destroyed
           * ====
           */
          function isContract(address account) internal view returns (bool) {
              // This method relies on extcodesize, which returns 0 for contracts in
              // construction, since the code is only stored at the end of the
              // constructor execution.
              uint256 size;
              // solhint-disable-next-line no-inline-assembly
              assembly { size := extcodesize(account) }
              return size > 0;
          }
          /**
           * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
           * `recipient`, forwarding all available gas and reverting on errors.
           *
           * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
           * of certain opcodes, possibly making contracts go over the 2300 gas limit
           * imposed by `transfer`, making them unable to receive funds via
           * `transfer`. {sendValue} removes this limitation.
           *
           * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
           *
           * IMPORTANT: because control is transferred to `recipient`, care must be
           * taken to not create reentrancy vulnerabilities. Consider using
           * {ReentrancyGuard} or the
           * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
           */
          function sendValue(address payable recipient, uint256 amount) internal {
              require(address(this).balance >= amount, "Address: insufficient balance");
              // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
              (bool success, ) = recipient.call{ value: amount }("");
              require(success, "Address: unable to send value, recipient may have reverted");
          }
          /**
           * @dev Performs a Solidity function call using a low level `call`. A
           * plain`call` is an unsafe replacement for a function call: use this
           * function instead.
           *
           * If `target` reverts with a revert reason, it is bubbled up by this
           * function (like regular Solidity function calls).
           *
           * Returns the raw returned data. To convert to the expected return value,
           * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
           *
           * Requirements:
           *
           * - `target` must be a contract.
           * - calling `target` with `data` must not revert.
           *
           * _Available since v3.1._
           */
          function functionCall(address target, bytes memory data) internal returns (bytes memory) {
            return functionCall(target, data, "Address: low-level call failed");
          }
          /**
           * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
           * `errorMessage` as a fallback revert reason when `target` reverts.
           *
           * _Available since v3.1._
           */
          function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
              return functionCallWithValue(target, data, 0, errorMessage);
          }
          /**
           * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
           * but also transferring `value` wei to `target`.
           *
           * Requirements:
           *
           * - the calling contract must have an ETH balance of at least `value`.
           * - the called Solidity function must be `payable`.
           *
           * _Available since v3.1._
           */
          function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
              return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
          }
          /**
           * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
           * with `errorMessage` as a fallback revert reason when `target` reverts.
           *
           * _Available since v3.1._
           */
          function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
              require(address(this).balance >= value, "Address: insufficient balance for call");
              require(isContract(target), "Address: call to non-contract");
              // solhint-disable-next-line avoid-low-level-calls
              (bool success, bytes memory returndata) = target.call{ value: value }(data);
              return _verifyCallResult(success, returndata, errorMessage);
          }
          /**
           * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
           * but performing a static call.
           *
           * _Available since v3.3._
           */
          function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
              return functionStaticCall(target, data, "Address: low-level static call failed");
          }
          /**
           * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
           * but performing a static call.
           *
           * _Available since v3.3._
           */
          function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
              require(isContract(target), "Address: static call to non-contract");
              // solhint-disable-next-line avoid-low-level-calls
              (bool success, bytes memory returndata) = target.staticcall(data);
              return _verifyCallResult(success, returndata, errorMessage);
          }
          /**
           * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
           * but performing a delegate call.
           *
           * _Available since v3.4._
           */
          function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
              return functionDelegateCall(target, data, "Address: low-level delegate call failed");
          }
          /**
           * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
           * but performing a delegate call.
           *
           * _Available since v3.4._
           */
          function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
              require(isContract(target), "Address: delegate call to non-contract");
              // solhint-disable-next-line avoid-low-level-calls
              (bool success, bytes memory returndata) = target.delegatecall(data);
              return _verifyCallResult(success, returndata, errorMessage);
          }
          function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
              if (success) {
                  return returndata;
              } else {
                  // Look for revert reason and bubble it up if present
                  if (returndata.length > 0) {
                      // The easiest way to bubble the revert reason is using memory via assembly
                      // solhint-disable-next-line no-inline-assembly
                      assembly {
                          let returndata_size := mload(returndata)
                          revert(add(32, returndata), returndata_size)
                      }
                  } else {
                      revert(errorMessage);
                  }
              }
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      /**
       * @dev Library for reading and writing primitive types to specific storage slots.
       *
       * Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
       * This library helps with reading and writing to such slots without the need for inline assembly.
       *
       * The functions in this library return Slot structs that contain a `value` member that can be used to read or write.
       *
       * Example usage to set ERC1967 implementation slot:
       * ```
       * contract ERC1967 {
       *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
       *
       *     function _getImplementation() internal view returns (address) {
       *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
       *     }
       *
       *     function _setImplementation(address newImplementation) internal {
       *         require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
       *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
       *     }
       * }
       * ```
       *
       * _Available since v4.1 for `address`, `bool`, `bytes32`, and `uint256`._
       */
      library StorageSlot {
          struct AddressSlot {
              address value;
          }
          struct BooleanSlot {
              bool value;
          }
          struct Bytes32Slot {
              bytes32 value;
          }
          struct Uint256Slot {
              uint256 value;
          }
          /**
           * @dev Returns an `AddressSlot` with member `value` located at `slot`.
           */
          function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
              assembly {
                  r.slot := slot
              }
          }
          /**
           * @dev Returns an `BooleanSlot` with member `value` located at `slot`.
           */
          function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
              assembly {
                  r.slot := slot
              }
          }
          /**
           * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
           */
          function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
              assembly {
                  r.slot := slot
              }
          }
          /**
           * @dev Returns an `Uint256Slot` with member `value` located at `slot`.
           */
          function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
              assembly {
                  r.slot := slot
              }
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      import "../utils/Context.sol";
      /**
       * @dev Contract module which provides a basic access control mechanism, where
       * there is an account (an owner) that can be granted exclusive access to
       * specific functions.
       *
       * By default, the owner account will be the one that deploys the contract. This
       * can later be changed with {transferOwnership}.
       *
       * This module is used through inheritance. It will make available the modifier
       * `onlyOwner`, which can be applied to your functions to restrict their use to
       * the owner.
       */
      abstract contract Ownable is Context {
          address private _owner;
          event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
          /**
           * @dev Initializes the contract setting the deployer as the initial owner.
           */
          constructor () {
              address msgSender = _msgSender();
              _owner = msgSender;
              emit OwnershipTransferred(address(0), msgSender);
          }
          /**
           * @dev Returns the address of the current owner.
           */
          function owner() public view virtual returns (address) {
              return _owner;
          }
          /**
           * @dev Throws if called by any account other than the owner.
           */
          modifier onlyOwner() {
              require(owner() == _msgSender(), "Ownable: caller is not the owner");
              _;
          }
          /**
           * @dev Leaves the contract without owner. It will not be possible to call
           * `onlyOwner` functions anymore. Can only be called by the current owner.
           *
           * NOTE: Renouncing ownership will leave the contract without an owner,
           * thereby removing any functionality that is only available to the owner.
           */
          function renounceOwnership() public virtual onlyOwner {
              emit OwnershipTransferred(_owner, address(0));
              _owner = address(0);
          }
          /**
           * @dev Transfers ownership of the contract to a new account (`newOwner`).
           * Can only be called by the current owner.
           */
          function transferOwnership(address newOwner) public virtual onlyOwner {
              require(newOwner != address(0), "Ownable: new owner is the zero address");
              emit OwnershipTransferred(_owner, newOwner);
              _owner = newOwner;
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      /*
       * @dev Provides information about the current execution context, including the
       * sender of the transaction and its data. While these are generally available
       * via msg.sender and msg.data, they should not be accessed in such a direct
       * manner, since when dealing with meta-transactions the account sending and
       * paying for execution may not be the actual sender (as far as an application
       * is concerned).
       *
       * This contract is only required for intermediate, library-like contracts.
       */
      abstract contract Context {
          function _msgSender() internal view virtual returns (address) {
              return msg.sender;
          }
          function _msgData() internal view virtual returns (bytes calldata) {
              this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
              return msg.data;
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      import "../ERC1967/ERC1967Upgrade.sol";
      /**
       * @dev Base contract for building openzeppelin-upgrades compatible implementations for the {ERC1967Proxy}. It includes
       * publicly available upgrade functions that are called by the plugin and by the secure upgrade mechanism to verify
       * continuation of the upgradability.
       *
       * The {_authorizeUpgrade} function MUST be overridden to include access restriction to the upgrade mechanism.
       *
       * _Available since v4.1._
       */
      abstract contract UUPSUpgradeable is ERC1967Upgrade {
          function upgradeTo(address newImplementation) external virtual {
              _authorizeUpgrade(newImplementation);
              _upgradeToAndCallSecure(newImplementation, bytes(""), false);
          }
          function upgradeToAndCall(address newImplementation, bytes memory data) external payable virtual {
              _authorizeUpgrade(newImplementation);
              _upgradeToAndCallSecure(newImplementation, data, true);
          }
          function _authorizeUpgrade(address newImplementation) internal virtual;
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.2;
      import "@openzeppelin/contracts/proxy/utils/UUPSUpgradeable.sol";
      abstract contract Proxiable is UUPSUpgradeable {
          function _authorizeUpgrade(address newImplementation) internal override {
              _beforeUpgrade(newImplementation);
          }
          function _beforeUpgrade(address newImplementation) internal virtual;
      }
      contract ChildOfProxiable is Proxiable {
          function _beforeUpgrade(address newImplementation) internal virtual override {}
      }
      

      File 2 of 3: Strong
      {"Address.sol":{"content":"// SPDX-License-Identifier: MIT\npragma solidity \u003e0.6.99 \u003c0.8.0;\n\n/**\n * @dev Collection of functions related to the address type\n */\nlibrary Address {\n    /**\n     * @dev Returns true if `account` is a contract.\n     *\n     * [IMPORTANT]\n     * ====\n     * It is unsafe to assume that an address for which this function returns\n     * false is an externally-owned account (EOA) and not a contract.\n     *\n     * Among others, `isContract` will return false for the following\n     * types of addresses:\n     *\n     *  - an externally-owned account\n     *  - a contract in construction\n     *  - an address where a contract will be created\n     *  - an address where a contract lived, but was destroyed\n     * ====\n     */\n    function isContract(address account) internal view returns (bool) {\n        // This method relies in extcodesize, which returns 0 for contracts in\n        // construction, since the code is only stored at the end of the\n        // constructor execution.\n\n        uint256 size;\n        // solhint-disable-next-line no-inline-assembly\n        assembly { size := extcodesize(account) }\n        return size \u003e 0;\n    }\n\n    /**\n     * @dev Replacement for Solidity\u0027s `transfer`: sends `amount` wei to\n     * `recipient`, forwarding all available gas and reverting on errors.\n     *\n     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost\n     * of certain opcodes, possibly making contracts go over the 2300 gas limit\n     * imposed by `transfer`, making them unable to receive funds via\n     * `transfer`. {sendValue} removes this limitation.\n     *\n     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].\n     *\n     * IMPORTANT: because control is transferred to `recipient`, care must be\n     * taken to not create reentrancy vulnerabilities. Consider using\n     * {ReentrancyGuard} or the\n     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].\n     */\n    function sendValue(address payable recipient, uint256 amount) internal {\n        require(address(this).balance \u003e= amount, \"Address: insufficient balance\");\n\n        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value\n        (bool success, ) = recipient.call{ value: amount }(\"\");\n        require(success, \"Address: unable to send value, recipient may have reverted\");\n    }\n\n    /**\n     * @dev Performs a Solidity function call using a low level `call`. A\n     * plain`call` is an unsafe replacement for a function call: use this\n     * function instead.\n     *\n     * If `target` reverts with a revert reason, it is bubbled up by this\n     * function (like regular Solidity function calls).\n     *\n     * Returns the raw returned data. To convert to the expected return value,\n     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].\n     *\n     * Requirements:\n     *\n     * - `target` must be a contract.\n     * - calling `target` with `data` must not revert.\n     *\n     * _Available since v3.1._\n     */\n    function functionCall(address target, bytes memory data) internal returns (bytes memory) {\n      return functionCall(target, data, \"Address: low-level call failed\");\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with\n     * `errorMessage` as a fallback revert reason when `target` reverts.\n     *\n     * _Available since v3.1._\n     */\n    function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {\n        return _functionCallWithValue(target, data, 0, errorMessage);\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],\n     * but also transferring `value` wei to `target`.\n     *\n     * Requirements:\n     *\n     * - the calling contract must have an ETH balance of at least `value`.\n     * - the called Solidity function must be `payable`.\n     *\n     * _Available since v3.1._\n     */\n    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {\n        return functionCallWithValue(target, data, value, \"Address: low-level call with value failed\");\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but\n     * with `errorMessage` as a fallback revert reason when `target` reverts.\n     *\n     * _Available since v3.1._\n     */\n    function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {\n        require(address(this).balance \u003e= value, \"Address: insufficient balance for call\");\n        return _functionCallWithValue(target, data, value, errorMessage);\n    }\n\n    function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) {\n        require(isContract(target), \"Address: call to non-contract\");\n\n        // solhint-disable-next-line avoid-low-level-calls\n        (bool success, bytes memory returndata) = target.call{ value: weiValue }(data);\n        if (success) {\n            return returndata;\n        } else {\n            // Look for revert reason and bubble it up if present\n            if (returndata.length \u003e 0) {\n                // The easiest way to bubble the revert reason is using memory via assembly\n\n                // solhint-disable-next-line no-inline-assembly\n                assembly {\n                    let returndata_size := mload(returndata)\n                    revert(add(32, returndata), returndata_size)\n                }\n            } else {\n                revert(errorMessage);\n            }\n        }\n    }\n}\n"},"Context.sol":{"content":"// SPDX-License-Identifier: MIT\npragma solidity \u003e0.6.99 \u003c0.8.0;\n\n/**\n * @dev Provides information about the current execution context, including the\n * sender of the transaction and its data. While these are generally available\n * via msg.sender and msg.data, they should not be accessed in such a direct\n * manner, since when dealing with GSN meta-transactions the account sending and\n * paying for execution may not be the actual sender (as far as an application\n * is concerned).\n *\n * This contract is only required for intermediate, library-like contracts.\n */\nabstract contract Context {\n    function _msgSender() internal view virtual returns (address payable) {\n        return msg.sender;\n    }\n\n    function _msgData() internal view virtual returns (bytes memory) {\n        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691\n        return msg.data;\n    }\n}\n"},"IERC20.sol":{"content":"// SPDX-License-Identifier: MIT\npragma solidity \u003e0.6.99 \u003c0.8.0;\n\n/**\n * @dev Interface of the ERC20 standard as defined in the EIP.\n */\ninterface IERC20 {\n    /**\n     * @dev Returns the amount of tokens in existence.\n     */\n    function totalSupply() external view returns (uint256);\n\n    /**\n     * @dev Returns the amount of tokens owned by `account`.\n     */\n    function balanceOf(address account) external view returns (uint256);\n\n    /**\n     * @dev Moves `amount` tokens from the caller\u0027s account to `recipient`.\n     *\n     * Returns a boolean value indicating whether the operation succeeded.\n     *\n     * Emits a {Transfer} event.\n     */\n    function transfer(address recipient, uint256 amount) external returns (bool);\n\n    /**\n     * @dev Returns the remaining number of tokens that `spender` will be\n     * allowed to spend on behalf of `owner` through {transferFrom}. This is\n     * zero by default.\n     *\n     * This value changes when {approve} or {transferFrom} are called.\n     */\n    function allowance(address owner, address spender) external view returns (uint256);\n\n    /**\n     * @dev Sets `amount` as the allowance of `spender` over the caller\u0027s tokens.\n     *\n     * Returns a boolean value indicating whether the operation succeeded.\n     *\n     * IMPORTANT: Beware that changing an allowance with this method brings the risk\n     * that someone may use both the old and the new allowance by unfortunate\n     * transaction ordering. One possible solution to mitigate this race\n     * condition is to first reduce the spender\u0027s allowance to 0 and set the\n     * desired value afterwards:\n     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729\n     *\n     * Emits an {Approval} event.\n     */\n    function approve(address spender, uint256 amount) external returns (bool);\n\n    /**\n     * @dev Moves `amount` tokens from `sender` to `recipient` using the\n     * allowance mechanism. `amount` is then deducted from the caller\u0027s\n     * allowance.\n     *\n     * Returns a boolean value indicating whether the operation succeeded.\n     *\n     * Emits a {Transfer} event.\n     */\n    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);\n\n    /**\n     * @dev Emitted when `value` tokens are moved from one account (`from`) to\n     * another (`to`).\n     *\n     * Note that `value` may be zero.\n     */\n    event Transfer(address indexed from, address indexed to, uint256 value);\n\n    /**\n     * @dev Emitted when the allowance of a `spender` for an `owner` is set by\n     * a call to {approve}. `value` is the new allowance.\n     */\n    event Approval(address indexed owner, address indexed spender, uint256 value);\n}\n"},"SafeMath.sol":{"content":"// SPDX-License-Identifier: MIT\npragma solidity \u003e0.6.99 \u003c0.8.0;\n\n/**\n * @dev Wrappers over Solidity\u0027s arithmetic operations with added overflow\n * checks.\n *\n * Arithmetic operations in Solidity wrap on overflow. This can easily result\n * in bugs, because programmers usually assume that an overflow raises an\n * error, which is the standard behavior in high level programming languages.\n * `SafeMath` restores this intuition by reverting the transaction when an\n * operation overflows.\n *\n * Using this library instead of the unchecked operations eliminates an entire\n * class of bugs, so it\u0027s recommended to use it always.\n */\nlibrary SafeMath {\n    /**\n     * @dev Returns the addition of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity\u0027s `+` operator.\n     *\n     * Requirements:\n     *\n     * - Addition cannot overflow.\n     */\n    function add(uint256 a, uint256 b) internal pure returns (uint256) {\n        uint256 c = a + b;\n        require(c \u003e= a, \"SafeMath: addition overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the subtraction of two unsigned integers, reverting on\n     * overflow (when the result is negative).\n     *\n     * Counterpart to Solidity\u0027s `-` operator.\n     *\n     * Requirements:\n     *\n     * - Subtraction cannot overflow.\n     */\n    function sub(uint256 a, uint256 b) internal pure returns (uint256) {\n        return sub(a, b, \"SafeMath: subtraction overflow\");\n    }\n\n    /**\n     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on\n     * overflow (when the result is negative).\n     *\n     * Counterpart to Solidity\u0027s `-` operator.\n     *\n     * Requirements:\n     *\n     * - Subtraction cannot overflow.\n     */\n    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\n        require(b \u003c= a, errorMessage);\n        uint256 c = a - b;\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the multiplication of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity\u0027s `*` operator.\n     *\n     * Requirements:\n     *\n     * - Multiplication cannot overflow.\n     */\n    function mul(uint256 a, uint256 b) internal pure returns (uint256) {\n        // Gas optimization: this is cheaper than requiring \u0027a\u0027 not being zero, but the\n        // benefit is lost if \u0027b\u0027 is also tested.\n        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522\n        if (a == 0) {\n            return 0;\n        }\n\n        uint256 c = a * b;\n        require(c / a == b, \"SafeMath: multiplication overflow\");\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the integer division of two unsigned integers. Reverts on\n     * division by zero. The result is rounded towards zero.\n     *\n     * Counterpart to Solidity\u0027s `/` operator. Note: this function uses a\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\n     * uses an invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function div(uint256 a, uint256 b) internal pure returns (uint256) {\n        return div(a, b, \"SafeMath: division by zero\");\n    }\n\n    /**\n     * @dev Returns the integer division of two unsigned integers. Reverts with custom message on\n     * division by zero. The result is rounded towards zero.\n     *\n     * Counterpart to Solidity\u0027s `/` operator. Note: this function uses a\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\n     * uses an invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\n        require(b \u003e 0, errorMessage);\n        uint256 c = a / b;\n        // assert(a == b * c + a % b); // There is no case in which this doesn\u0027t hold\n\n        return c;\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * Reverts when dividing by zero.\n     *\n     * Counterpart to Solidity\u0027s `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function mod(uint256 a, uint256 b) internal pure returns (uint256) {\n        return mod(a, b, \"SafeMath: modulo by zero\");\n    }\n\n    /**\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * Reverts with custom message when dividing by zero.\n     *\n     * Counterpart to Solidity\u0027s `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\n        require(b != 0, errorMessage);\n        return a % b;\n    }\n}\n"},"Strong.sol":{"content":"// SPDX-License-Identifier: MIT\npragma solidity \u003e0.6.99 \u003c0.8.0;\n\nimport \"./Context.sol\";\nimport \"./IERC20.sol\";\nimport \"./SafeMath.sol\";\nimport \"./Address.sol\";\n\n/**\n * @dev Implementation of the {IERC20} interface.\n *\n * We have followed general OpenZeppelin guidelines: functions revert instead\n * of returning `false` on failure. This behavior is nonetheless conventional\n * and does not conflict with the expectations of ERC20 applications.\n *\n * Additionally, an {Approval} event is emitted on calls to {transferFrom}.\n * This allows applications to reconstruct the allowance for all accounts just\n * by listening to said events. Other implementations of the EIP may not emit\n * these events, as it isn\u0027t required by the specification.\n *\n * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}\n * functions have been added to mitigate the well-known issues around setting\n * allowances. See {IERC20-approve}.\n */\ncontract Strong is Context, IERC20 {\n    using SafeMath for uint256;\n    using Address for address;\n\n    mapping (address =\u003e uint256) private _balances;\n\n    mapping (address =\u003e mapping (address =\u003e uint256)) private _allowances;\n\n    uint256 private _totalSupply;\n\n    string private _name = \"Strong\";\n    string private _symbol = \"STRONG\";\n    uint8 private _decimals = 18;\n\n    /**\n     * @dev Sets the specified balances for the specified addresses. \u0027addresses\u0027 and \u0027balances\u0027 arrays\n     * are to be index aligned.\n     */\n    constructor (address[] memory addresses, uint[] memory balances) {\n        require(addresses.length \u003e 0 \u0026\u0026 balances.length \u003e 0, \"STRONG: array length must be greater than zero\");\n        require(addresses.length == balances.length, \"STRONG: arrays length mismatch\");\n\n        for (uint i = 0; i \u003c addresses.length; i++) {\n            _mint(addresses[i], balances[i]);\n        }\n        require(_totalSupply == 10000000e18, \"STRONG: totalSupply must equal 10 million\");\n    }\n\n    /**\n     * @dev Returns the name of the token.\n     */\n    function name() public view returns (string memory) {\n        return _name;\n    }\n\n    /**\n     * @dev Returns the symbol of the token, usually a shorter version of the\n     * name.\n     */\n    function symbol() public view returns (string memory) {\n        return _symbol;\n    }\n\n    /**\n     * @dev Returns the number of decimals used to get its user representation.\n     * For example, if `decimals` equals `2`, a balance of `505` tokens should\n     * be displayed to a user as `5,05` (`505 / 10 ** 2`).\n     *\n     * Tokens usually opt for a value of 18, imitating the relationship between\n     * Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is\n     * called.\n     *\n     * NOTE: This information is only used for _display_ purposes: it in\n     * no way affects any of the arithmetic of the contract, including\n     * {IERC20-balanceOf} and {IERC20-transfer}.\n     */\n    function decimals() public view returns (uint8) {\n        return _decimals;\n    }\n\n    /**\n     * @dev See {IERC20-totalSupply}.\n     */\n    function totalSupply() public view override returns (uint256) {\n        return _totalSupply;\n    }\n\n    /**\n     * @dev See {IERC20-balanceOf}.\n     */\n    function balanceOf(address account) public view override returns (uint256) {\n        return _balances[account];\n    }\n\n    /**\n     * @dev See {IERC20-transfer}.\n     *\n     * Requirements:\n     *\n     * - `recipient` cannot be the zero address.\n     * - the caller must have a balance of at least `amount`.\n     */\n    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {\n        _transfer(_msgSender(), recipient, amount);\n        return true;\n    }\n\n    /**\n     * @dev See {IERC20-allowance}.\n     */\n    function allowance(address owner, address spender) public view virtual override returns (uint256) {\n        return _allowances[owner][spender];\n    }\n\n    /**\n     * @dev See {IERC20-approve}.\n     *\n     * Requirements:\n     *\n     * - `spender` cannot be the zero address.\n     */\n    function approve(address spender, uint256 amount) public virtual override returns (bool) {\n        _approve(_msgSender(), spender, amount);\n        return true;\n    }\n\n    /**\n     * @dev See {IERC20-transferFrom}.\n     *\n     * Emits an {Approval} event indicating the updated allowance. This is not\n     * required by the EIP. See the note at the beginning of {ERC20};\n     *\n     * Requirements:\n     * - `sender` and `recipient` cannot be the zero address.\n     * - `sender` must have a balance of at least `amount`.\n     * - the caller must have allowance for ``sender``\u0027s tokens of at least\n     * `amount`.\n     */\n    function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {\n        _transfer(sender, recipient, amount);\n        _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, \"STRONG: transfer amount exceeds allowance\"));\n        return true;\n    }\n\n    /**\n     * @dev Atomically increases the allowance granted to `spender` by the caller.\n     *\n     * This is an alternative to {approve} that can be used as a mitigation for\n     * problems described in {IERC20-approve}.\n     *\n     * Emits an {Approval} event indicating the updated allowance.\n     *\n     * Requirements:\n     *\n     * - `spender` cannot be the zero address.\n     */\n    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {\n        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));\n        return true;\n    }\n\n    /**\n     * @dev Atomically decreases the allowance granted to `spender` by the caller.\n     *\n     * This is an alternative to {approve} that can be used as a mitigation for\n     * problems described in {IERC20-approve}.\n     *\n     * Emits an {Approval} event indicating the updated allowance.\n     *\n     * Requirements:\n     *\n     * - `spender` cannot be the zero address.\n     * - `spender` must have allowance for the caller of at least\n     * `subtractedValue`.\n     */\n    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {\n        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, \"STRONG: decreased allowance below zero\"));\n        return true;\n    }\n\n    /**\n     * @dev Moves tokens `amount` from `sender` to `recipient`.\n     *\n     * This is internal function is equivalent to {transfer}, and can be used to\n     * e.g. implement automatic token fees, slashing mechanisms, etc.\n     *\n     * Emits a {Transfer} event.\n     *\n     * Requirements:\n     *\n     * - `sender` cannot be the zero address.\n     * - `recipient` cannot be the zero address.\n     * - `sender` must have a balance of at least `amount`.\n     */\n    function _transfer(address sender, address recipient, uint256 amount) internal virtual {\n        require(sender != address(0), \"STRONG: transfer from the zero address\");\n        require(recipient != address(0), \"STRONG: transfer to the zero address\");\n\n        _beforeTokenTransfer(sender, recipient, amount);\n\n        _balances[sender] = _balances[sender].sub(amount, \"STRONG: transfer amount exceeds balance\");\n        _balances[recipient] = _balances[recipient].add(amount);\n        emit Transfer(sender, recipient, amount);\n    }\n\n    /** @dev Creates `amount` tokens and assigns them to `account`, increasing\n     * the total supply.\n     *\n     * Emits a {Transfer} event with `from` set to the zero address.\n     *\n     * Requirements\n     *\n     * - `to` cannot be the zero address.\n     */\n    function _mint(address account, uint256 amount) internal virtual {\n        require(account != address(0), \"STRONG: mint to the zero address\");\n\n        _beforeTokenTransfer(address(0), account, amount);\n\n        _totalSupply = _totalSupply.add(amount);\n        _balances[account] = _balances[account].add(amount);\n        emit Transfer(address(0), account, amount);\n    }\n\n    /**\n     * @dev Sets `amount` as the allowance of `spender` over the `owner`s tokens.\n     *\n     * This is internal function is equivalent to `approve`, and can be used to\n     * e.g. set automatic allowances for certain subsystems, etc.\n     *\n     * Emits an {Approval} event.\n     *\n     * Requirements:\n     *\n     * - `owner` cannot be the zero address.\n     * - `spender` cannot be the zero address.\n     */\n    function _approve(address owner, address spender, uint256 amount) internal virtual {\n        require(owner != address(0), \"STRONG: approve from the zero address\");\n        require(spender != address(0), \"STRONG: approve to the zero address\");\n\n        _allowances[owner][spender] = amount;\n        emit Approval(owner, spender, amount);\n    }\n\n    /**\n     * @dev Hook that is called before any transfer of tokens. This includes\n     * minting and burning.\n     *\n     * Calling conditions:\n     *\n     * - when `from` and `to` are both non-zero, `amount` of ``from``\u0027s tokens\n     * will be to transferred to `to`.\n     * - when `from` is zero, `amount` tokens will be minted for `to`.\n     * - when `to` is zero, `amount` of ``from``\u0027s tokens will be burned.\n     * - `from` and `to` are never both zero.\n     *\n     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].\n     */\n    function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual { }\n}\n"}}

      File 3 of 3: NodesV1
      // SPDX-License-Identifier: MIT
      pragma solidity 0.6.12;
      import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
      import "./interfaces/IERC1155Preset.sol";
      import "./interfaces/StrongPoolInterface.sol";
      import "./lib/AdminAccessControl.sol";
      import "./lib/rewards.sol";
      contract NodesV1 is AdminAccessControl {
        event Requested(address indexed miner);
        event Claimed(address indexed miner, uint256 reward);
        event Paid(address indexed entity, uint128 nodeId, bool isRenewal, uint256 upToBlockNumber);
        IERC20 public strongToken;
        StrongPoolInterface public strongPool;
        bool public initDone;
        uint256 public activeEntities;
        address payable public feeCollector;
        uint256 public rewardPerBlockNumerator;
        uint256 public rewardPerBlockDenominator;
        uint256 public rewardPerBlockNumeratorNew;
        uint256 public rewardPerBlockDenominatorNew;
        uint256 public rewardPerBlockNewEffectiveBlock;
        uint256 public claimingFeeNumerator;
        uint256 public claimingFeeDenominator;
        uint256 public requestingFeeInWei;
        uint256 public strongFeeInWei;
        uint256 public recurringFeeInWei;
        uint256 public recurringPaymentCycleInBlocks;
        uint256 public rewardBalance;
        uint256 public claimingFeeInWei;
        uint256 public gracePeriodInBlocks;
        uint128 public maxNodes;
        uint256 public maxPaymentPeriods;
        mapping(bytes => uint256) public entityNodePaidOnBlock;
        mapping(bytes => uint256) public entityNodeClaimedOnBlock;
        mapping(address => uint128) public entityNodeCount;
        function init(
          address _strongTokenAddress,
          address _strongPoolAddress,
          uint256 _rewardPerBlockNumeratorValue,
          uint256 _rewardPerBlockDenominatorValue,
          uint256 _requestingFeeInWeiValue,
          uint256 _strongFeeInWeiValue,
          uint256 _recurringFeeInWeiValue,
          uint256 _recurringPaymentCycleInBlocksValue,
          uint256 _claimingFeeNumeratorValue,
          uint256 _claimingFeeDenominatorValue
        ) public {
          require(!initDone, "init done");
          strongToken = IERC20(_strongTokenAddress);
          strongPool = StrongPoolInterface(_strongPoolAddress);
          rewardPerBlockNumerator = _rewardPerBlockNumeratorValue;
          rewardPerBlockDenominator = _rewardPerBlockDenominatorValue;
          requestingFeeInWei = _requestingFeeInWeiValue;
          strongFeeInWei = _strongFeeInWeiValue;
          recurringFeeInWei = _recurringFeeInWeiValue;
          claimingFeeNumerator = _claimingFeeNumeratorValue;
          claimingFeeDenominator = _claimingFeeDenominatorValue;
          recurringPaymentCycleInBlocks = _recurringPaymentCycleInBlocksValue;
          maxNodes = 100;
          initDone = true;
        }
        //
        // Getters
        // -------------------------------------------------------------------------------------------------------------------
        function canBePaid(address _entity, uint128 _nodeId) public view returns (bool) {
          return !hasNodeExpired(_entity, _nodeId) && !hasMaxPayments(_entity, _nodeId);
        }
        function doesNodeExist(address _entity, uint128 _nodeId) public view returns (bool) {
          return entityNodePaidOnBlock[getNodeId(_entity, _nodeId)] > 0;
        }
        function hasNodeExpired(address _entity, uint128 _nodeId) public view returns (bool) {
          uint256 blockLastPaidOn = entityNodePaidOnBlock[getNodeId(_entity, _nodeId)];
          return block.number > blockLastPaidOn + recurringPaymentCycleInBlocks + gracePeriodInBlocks;
        }
        function hasMaxPayments(address _entity, uint128 _nodeId) public view returns (bool) {
          uint256 blockLastPaidOn = entityNodePaidOnBlock[getNodeId(_entity, _nodeId)];
          uint256 limit = block.number + recurringPaymentCycleInBlocks * maxPaymentPeriods;
          return blockLastPaidOn + recurringPaymentCycleInBlocks >= limit;
        }
        function getNodeId(address _entity, uint128 _nodeId) public view returns (bytes memory) {
          uint128 id = _nodeId != 0 ? _nodeId : entityNodeCount[_entity] + 1;
          return abi.encodePacked(_entity, id);
        }
        function getNodePaidOn(address _entity, uint128 _nodeId) public view returns (uint256) {
          return entityNodePaidOnBlock[getNodeId(_entity, _nodeId)];
        }
        function getReward(address _entity, uint128 _nodeId) public view returns (uint256) {
          return getRewardByBlock(_entity, _nodeId, block.number);
        }
        function getRewardAll(address _entity, uint256 _blockNumber) public view returns (uint256) {
          uint256 rewardsAll = 0;
          for (uint128 i = 1; i <= entityNodeCount[_entity]; i++) {
            rewardsAll = rewardsAll + getRewardByBlock(_entity, i, _blockNumber > 0 ? _blockNumber : block.number);
          }
          return rewardsAll;
        }
        function getRewardByBlock(address _entity, uint128 _nodeId, uint256 _blockNumber) public view returns (uint256) {
          bytes memory id = getNodeId(_entity, _nodeId);
          uint256 blockLastClaimedOn = entityNodeClaimedOnBlock[id] != 0 ? entityNodeClaimedOnBlock[id] : entityNodePaidOnBlock[id];
          if (_blockNumber > block.number) return 0;
          if (blockLastClaimedOn == 0) return 0;
          if (_blockNumber < blockLastClaimedOn) return 0;
          uint256[2] memory rewardBlocks = rewards.blocks(blockLastClaimedOn, rewardPerBlockNewEffectiveBlock, _blockNumber);
          uint256 rewardOld = rewardPerBlockDenominator > 0 ? rewardBlocks[0] * rewardPerBlockNumerator / rewardPerBlockDenominator : 0;
          uint256 rewardNew = rewardPerBlockDenominatorNew > 0 ? rewardBlocks[1] * rewardPerBlockNumeratorNew / rewardPerBlockDenominatorNew : 0;
          return rewardOld + rewardNew;
        }
        function isEntityActive(address _entity) public view returns (bool) {
          return doesNodeExist(_entity, 1) && !hasNodeExpired(_entity, 1);
        }
        //
        // Actions
        // -------------------------------------------------------------------------------------------------------------------
        function requestAccess() public payable {
          require(entityNodeCount[msg.sender] < maxNodes, "limit reached");
          require(msg.value == requestingFeeInWei, "invalid fee");
          uint128 nodeId = entityNodeCount[msg.sender] + 1;
          bytes memory id = getNodeId(msg.sender, nodeId);
          activeEntities ++;
          entityNodePaidOnBlock[id] = block.number;
          entityNodeClaimedOnBlock[id] = block.number;
          entityNodeCount[msg.sender] = entityNodeCount[msg.sender] + 1;
          feeCollector.transfer(msg.value);
          strongToken.transferFrom(msg.sender, feeCollector, strongFeeInWei);
          emit Paid(msg.sender, nodeId, false, entityNodePaidOnBlock[id] + recurringPaymentCycleInBlocks);
        }
        function payFee(uint128 _nodeId) public payable {
          address sender = msg.sender == address(this) ? tx.origin : msg.sender;
          bytes memory id = getNodeId(sender, _nodeId);
          require(doesNodeExist(sender, _nodeId), "doesnt exist");
          require(hasNodeExpired(sender, _nodeId) == false, "too late");
          require(hasMaxPayments(sender, _nodeId) == false, "too soon");
          require(msg.value == recurringFeeInWei, "invalid fee");
          feeCollector.transfer(msg.value);
          entityNodePaidOnBlock[id] = entityNodePaidOnBlock[id] + recurringPaymentCycleInBlocks;
          emit Paid(sender, _nodeId, true, entityNodePaidOnBlock[id]);
        }
        function claim(uint128 _nodeId, uint256 _blockNumber, bool _toStrongPool) public payable returns (bool) {
          address sender = msg.sender == address(this) ? tx.origin : msg.sender;
          bytes memory id = getNodeId(sender, _nodeId);
          uint256 blockLastClaimedOn = entityNodeClaimedOnBlock[id] != 0 ? entityNodeClaimedOnBlock[id] : entityNodePaidOnBlock[id];
          uint256 blockLastPaidOn = entityNodePaidOnBlock[id];
          require(blockLastClaimedOn != 0, "never claimed");
          require(_blockNumber <= block.number, "invalid block");
          require(_blockNumber > blockLastClaimedOn, "too soon");
          if (recurringFeeInWei != 0) {
            require(_blockNumber < blockLastPaidOn + recurringPaymentCycleInBlocks, "pay fee");
          }
          uint256 reward = getRewardByBlock(sender, _nodeId, _blockNumber);
          require(reward > 0, "no reward");
          uint256 fee = reward * claimingFeeNumerator / claimingFeeDenominator;
          require(msg.value >= fee, "invalid fee");
          feeCollector.transfer(msg.value);
          if (_toStrongPool) {
            strongToken.approve(address(strongPool), reward);
            strongPool.mineFor(sender, reward);
          } else {
            strongToken.transfer(sender, reward);
          }
          rewardBalance -= reward;
          entityNodeClaimedOnBlock[id] = _blockNumber;
          emit Claimed(sender, reward);
          return true;
        }
        function claimAll(uint256 _blockNumber, bool _toStrongPool) public payable {
          uint256 value = msg.value;
          for (uint16 i = 1; i <= entityNodeCount[msg.sender]; i++) {
            uint256 reward = getRewardByBlock(msg.sender, i, _blockNumber);
            uint256 fee = reward * claimingFeeNumerator / claimingFeeDenominator;
            require(value >= fee, "invalid fee");
            require(this.claim{value : fee}(i, _blockNumber, _toStrongPool), "claim failed");
            value -= fee;
          }
        }
        function payAll(uint256 _nodeCount) public payable {
          require(_nodeCount > 0, "invalid value");
          require(msg.value == recurringFeeInWei * _nodeCount, "invalid fee");
          for (uint16 nodeId = 1; nodeId <= entityNodeCount[msg.sender]; nodeId++) {
            if (!canBePaid(msg.sender, nodeId)) {
              continue;
            }
            this.payFee{value : recurringFeeInWei}(nodeId);
            _nodeCount -= 1;
          }
          require(_nodeCount == 0, "invalid count");
        }
        //
        // Admin
        // -------------------------------------------------------------------------------------------------------------------
        function deposit(uint256 _amount) public onlyRole(adminControl.SUPER_ADMIN()) {
          require(_amount > 0);
          strongToken.transferFrom(msg.sender, address(this), _amount);
          rewardBalance += _amount;
        }
        function withdraw(address _destination, uint256 _amount) public onlyRole(adminControl.SUPER_ADMIN()) {
          require(_amount > 0);
          require(rewardBalance >= _amount, "not enough");
          strongToken.transfer(_destination, _amount);
          rewardBalance -= _amount;
        }
        function updateFeeCollector(address payable _newFeeCollector) public onlyRole(adminControl.SUPER_ADMIN()) {
          require(_newFeeCollector != address(0));
          feeCollector = _newFeeCollector;
        }
        function updateRequestingFee(uint256 _feeInWei) public onlyRole(adminControl.SERVICE_ADMIN()) {
          requestingFeeInWei = _feeInWei;
        }
        function updateStrongFee(uint256 _feeInWei) public onlyRole(adminControl.SERVICE_ADMIN()) {
          strongFeeInWei = _feeInWei;
        }
        function updateClaimingFee(uint256 _numerator, uint256 _denominator) public onlyRole(adminControl.SERVICE_ADMIN()) {
          require(_denominator != 0);
          claimingFeeNumerator = _numerator;
          claimingFeeDenominator = _denominator;
        }
        function updateRecurringFee(uint256 _feeInWei) public onlyRole(adminControl.SERVICE_ADMIN()) {
          recurringFeeInWei = _feeInWei;
        }
        function updateRecurringPaymentCycleInBlocks(uint256 _blocks) public onlyRole(adminControl.SERVICE_ADMIN()) {
          require(_blocks > 0);
          recurringPaymentCycleInBlocks = _blocks;
        }
        function updateGracePeriodInBlocks(uint256 _blocks) public onlyRole(adminControl.SERVICE_ADMIN()) {
          require(_blocks > 0);
          gracePeriodInBlocks = _blocks;
        }
        function updateLimits(uint128 _maxNodes, uint256 _maxPaymentPeriods) public onlyRole(adminControl.SERVICE_ADMIN()) {
          maxNodes = _maxNodes;
          maxPaymentPeriods = _maxPaymentPeriods;
        }
        function updateRewardPerBlock(uint256 _numerator, uint256 _denominator) public onlyRole(adminControl.SERVICE_ADMIN()) {
          require(_denominator != 0);
          rewardPerBlockNumerator = _numerator;
          rewardPerBlockDenominator = _denominator;
        }
        function updateRewardPerBlockNew(uint256 _numerator, uint256 _denominator, uint256 _effectiveBlock) public onlyRole(adminControl.SERVICE_ADMIN()) {
          require(_denominator != 0);
          rewardPerBlockNumeratorNew = _numerator;
          rewardPerBlockDenominatorNew = _denominator;
          rewardPerBlockNewEffectiveBlock = _effectiveBlock != 0 ? _effectiveBlock : block.number;
        }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity >=0.6.0 <0.8.0;
      /**
       * @dev Interface of the ERC20 standard as defined in the EIP.
       */
      interface IERC20 {
          /**
           * @dev Returns the amount of tokens in existence.
           */
          function totalSupply() external view returns (uint256);
          /**
           * @dev Returns the amount of tokens owned by `account`.
           */
          function balanceOf(address account) external view returns (uint256);
          /**
           * @dev Moves `amount` tokens from the caller's account to `recipient`.
           *
           * Returns a boolean value indicating whether the operation succeeded.
           *
           * Emits a {Transfer} event.
           */
          function transfer(address recipient, uint256 amount) external returns (bool);
          /**
           * @dev Returns the remaining number of tokens that `spender` will be
           * allowed to spend on behalf of `owner` through {transferFrom}. This is
           * zero by default.
           *
           * This value changes when {approve} or {transferFrom} are called.
           */
          function allowance(address owner, address spender) external view returns (uint256);
          /**
           * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
           *
           * Returns a boolean value indicating whether the operation succeeded.
           *
           * IMPORTANT: Beware that changing an allowance with this method brings the risk
           * that someone may use both the old and the new allowance by unfortunate
           * transaction ordering. One possible solution to mitigate this race
           * condition is to first reduce the spender's allowance to 0 and set the
           * desired value afterwards:
           * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
           *
           * Emits an {Approval} event.
           */
          function approve(address spender, uint256 amount) external returns (bool);
          /**
           * @dev Moves `amount` tokens from `sender` to `recipient` using the
           * allowance mechanism. `amount` is then deducted from the caller's
           * allowance.
           *
           * Returns a boolean value indicating whether the operation succeeded.
           *
           * Emits a {Transfer} event.
           */
          function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
          /**
           * @dev Emitted when `value` tokens are moved from one account (`from`) to
           * another (`to`).
           *
           * Note that `value` may be zero.
           */
          event Transfer(address indexed from, address indexed to, uint256 value);
          /**
           * @dev Emitted when the allowance of a `spender` for an `owner` is set by
           * a call to {approve}. `value` is the new allowance.
           */
          event Approval(address indexed owner, address indexed spender, uint256 value);
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.6.2;
      /**
       * @dev Required interface of an ERC1155 compliant contract, as defined in the
       * https://eips.ethereum.org/EIPS/eip-1155[EIP].
       *
       * _Available since v3.1._
       */
      interface IERC1155Preset {
          /**
           * @dev Emitted when `value` tokens of token type `id` are transferred from `from` to `to` by `operator`.
           */
          event TransferSingle(address indexed operator, address indexed from, address indexed to, uint256 id, uint256 value);
          /**
           * @dev Equivalent to multiple {TransferSingle} events, where `operator`, `from` and `to` are the same for all
           * transfers.
           */
          event TransferBatch(address indexed operator, address indexed from, address indexed to, uint256[] ids, uint256[] values);
          /**
           * @dev Emitted when `account` grants or revokes permission to `operator` to transfer their tokens, according to
           * `approved`.
           */
          event ApprovalForAll(address indexed account, address indexed operator, bool approved);
          /**
           * @dev Emitted when the URI for token type `id` changes to `value`, if it is a non-programmatic URI.
           *
           * If an {URI} event was emitted for `id`, the standard
           * https://eips.ethereum.org/EIPS/eip-1155#metadata-extensions[guarantees] that `value` will equal the value
           * returned by {IERC1155MetadataURI-uri}.
           */
          event URI(string value, uint256 indexed id);
          /**
           * @dev Returns the amount of tokens of token type `id` owned by `account`.
           *
           * Requirements:
           *
           * - `account` cannot be the zero address.
           */
          function balanceOf(address account, uint256 id) external view returns (uint256);
          /**
           * @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {balanceOf}.
           *
           * Requirements:
           *
           * - `accounts` and `ids` must have the same length.
           */
          function balanceOfBatch(address[] calldata accounts, uint256[] calldata ids) external view returns (uint256[] memory);
          /**
           * @dev Grants or revokes permission to `operator` to transfer the caller's tokens, according to `approved`,
           *
           * Emits an {ApprovalForAll} event.
           *
           * Requirements:
           *
           * - `operator` cannot be the caller.
           */
          function setApprovalForAll(address operator, bool approved) external;
          /**
           * @dev Returns true if `operator` is approved to transfer ``account``'s tokens.
           *
           * See {setApprovalForAll}.
           */
          function isApprovedForAll(address account, address operator) external view returns (bool);
          /**
           * @dev Transfers `amount` tokens of token type `id` from `from` to `to`.
           *
           * Emits a {TransferSingle} event.
           *
           * Requirements:
           *
           * - `to` cannot be the zero address.
           * - If the caller is not `from`, it must be have been approved to spend ``from``'s tokens via {setApprovalForAll}.
           * - `from` must have a balance of tokens of type `id` of at least `amount`.
           * - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155Received} and return the
           * acceptance magic value.
           */
          function safeTransferFrom(address from, address to, uint256 id, uint256 amount, bytes calldata data) external;
          /**
           * @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {safeTransferFrom}.
           *
           * Emits a {TransferBatch} event.
           *
           * Requirements:
           *
           * - `ids` and `amounts` must have the same length.
           * - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155BatchReceived} and return the
           * acceptance magic value.
           */
          function safeBatchTransferFrom(address from, address to, uint256[] calldata ids, uint256[] calldata amounts, bytes calldata data) external;
          /**
           * @dev Returns true if this contract implements the interface defined by
           * `interfaceId`. See the corresponding
           * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
           * to learn more about how these ids are created.
           *
           * This function call must use less than 30 000 gas.
           */
          function supportsInterface(bytes4 interfaceId) external view returns (bool);
          /**
           * @dev Creates `amount` new tokens for `to`, of token type `id`.
           *
           * See {ERC1155-_mint}.
           *
           * Requirements:
           *
           * - the caller must have the `MINTER_ROLE`.
           */
          function mint(address to, uint256 id, uint256 amount, bytes memory data) external;
          /**
           * @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] variant of {mint}.
           */
          function mintBatch(address to, uint256[] memory ids, uint256[] memory amounts, bytes memory data) external;
          function getOwnerIdByIndex(address owner, uint256 index) external view returns (uint256);
          function getOwnerIdIndex(address owner, uint256 id) external view returns (uint256);
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.6.12;
      interface StrongPoolInterface {
        function mineFor(address miner, uint256 amount) external;
      }
      // SPDX-License-Identifier: MIT
      pragma solidity 0.6.12;
      import "../interfaces/AdminControlInterface.sol";
      abstract contract AdminAccessControl {
        AdminControlInterface public adminControl;
        modifier onlyRole(uint8 _role) {
          require(address(adminControl) == address(0) || adminControl.hasRole(_role, msg.sender), 'no access');
          _;
        }
        function addAdminControlContract(address _contract) public onlyRole(0) {
          adminControl = AdminControlInterface(_contract);
        }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity 0.6.12;
      import "@openzeppelin/contracts/math/SafeMath.sol";
      library rewards {
          using SafeMath for uint256;
          function blocks(uint256 lastClaimedOnBlock, uint256 newRewardBlock, uint256 blockNumber) internal pure returns (uint256[2] memory) {
              if (lastClaimedOnBlock >= blockNumber) return [uint256(0), uint256(0)];
              if (blockNumber <= newRewardBlock || newRewardBlock == 0) {
                  return [blockNumber.sub(lastClaimedOnBlock), uint256(0)];
              }
              else if (lastClaimedOnBlock >= newRewardBlock) {
                  return [uint256(0), blockNumber.sub(lastClaimedOnBlock)];
              }
              else {
                  return [newRewardBlock.sub(lastClaimedOnBlock), blockNumber.sub(newRewardBlock)];
              }
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity 0.6.12;
      interface AdminControlInterface {
        function hasRole(uint8 _role, address _account) external view returns (bool);
        function SUPER_ADMIN() external view returns (uint8);
        function ADMIN() external view returns (uint8);
        function SERVICE_ADMIN() external view returns (uint8);
      }
      // SPDX-License-Identifier: MIT
      pragma solidity >=0.6.0 <0.8.0;
      /**
       * @dev Wrappers over Solidity's arithmetic operations with added overflow
       * checks.
       *
       * Arithmetic operations in Solidity wrap on overflow. This can easily result
       * in bugs, because programmers usually assume that an overflow raises an
       * error, which is the standard behavior in high level programming languages.
       * `SafeMath` restores this intuition by reverting the transaction when an
       * operation overflows.
       *
       * Using this library instead of the unchecked operations eliminates an entire
       * class of bugs, so it's recommended to use it always.
       */
      library SafeMath {
          /**
           * @dev Returns the addition of two unsigned integers, with an overflow flag.
           *
           * _Available since v3.4._
           */
          function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
              uint256 c = a + b;
              if (c < a) return (false, 0);
              return (true, c);
          }
          /**
           * @dev Returns the substraction of two unsigned integers, with an overflow flag.
           *
           * _Available since v3.4._
           */
          function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
              if (b > a) return (false, 0);
              return (true, a - b);
          }
          /**
           * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
           *
           * _Available since v3.4._
           */
          function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
              // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
              // benefit is lost if 'b' is also tested.
              // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
              if (a == 0) return (true, 0);
              uint256 c = a * b;
              if (c / a != b) return (false, 0);
              return (true, c);
          }
          /**
           * @dev Returns the division of two unsigned integers, with a division by zero flag.
           *
           * _Available since v3.4._
           */
          function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
              if (b == 0) return (false, 0);
              return (true, a / b);
          }
          /**
           * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
           *
           * _Available since v3.4._
           */
          function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
              if (b == 0) return (false, 0);
              return (true, a % b);
          }
          /**
           * @dev Returns the addition of two unsigned integers, reverting on
           * overflow.
           *
           * Counterpart to Solidity's `+` operator.
           *
           * Requirements:
           *
           * - Addition cannot overflow.
           */
          function add(uint256 a, uint256 b) internal pure returns (uint256) {
              uint256 c = a + b;
              require(c >= a, "SafeMath: addition overflow");
              return c;
          }
          /**
           * @dev Returns the subtraction of two unsigned integers, reverting on
           * overflow (when the result is negative).
           *
           * Counterpart to Solidity's `-` operator.
           *
           * Requirements:
           *
           * - Subtraction cannot overflow.
           */
          function sub(uint256 a, uint256 b) internal pure returns (uint256) {
              require(b <= a, "SafeMath: subtraction overflow");
              return a - b;
          }
          /**
           * @dev Returns the multiplication of two unsigned integers, reverting on
           * overflow.
           *
           * Counterpart to Solidity's `*` operator.
           *
           * Requirements:
           *
           * - Multiplication cannot overflow.
           */
          function mul(uint256 a, uint256 b) internal pure returns (uint256) {
              if (a == 0) return 0;
              uint256 c = a * b;
              require(c / a == b, "SafeMath: multiplication overflow");
              return c;
          }
          /**
           * @dev Returns the integer division of two unsigned integers, reverting on
           * division by zero. The result is rounded towards zero.
           *
           * Counterpart to Solidity's `/` operator. Note: this function uses a
           * `revert` opcode (which leaves remaining gas untouched) while Solidity
           * uses an invalid opcode to revert (consuming all remaining gas).
           *
           * Requirements:
           *
           * - The divisor cannot be zero.
           */
          function div(uint256 a, uint256 b) internal pure returns (uint256) {
              require(b > 0, "SafeMath: division by zero");
              return a / b;
          }
          /**
           * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
           * reverting when dividing by zero.
           *
           * Counterpart to Solidity's `%` operator. This function uses a `revert`
           * opcode (which leaves remaining gas untouched) while Solidity uses an
           * invalid opcode to revert (consuming all remaining gas).
           *
           * Requirements:
           *
           * - The divisor cannot be zero.
           */
          function mod(uint256 a, uint256 b) internal pure returns (uint256) {
              require(b > 0, "SafeMath: modulo by zero");
              return a % b;
          }
          /**
           * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
           * overflow (when the result is negative).
           *
           * CAUTION: This function is deprecated because it requires allocating memory for the error
           * message unnecessarily. For custom revert reasons use {trySub}.
           *
           * Counterpart to Solidity's `-` operator.
           *
           * Requirements:
           *
           * - Subtraction cannot overflow.
           */
          function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
              require(b <= a, errorMessage);
              return a - b;
          }
          /**
           * @dev Returns the integer division of two unsigned integers, reverting with custom message on
           * division by zero. The result is rounded towards zero.
           *
           * CAUTION: This function is deprecated because it requires allocating memory for the error
           * message unnecessarily. For custom revert reasons use {tryDiv}.
           *
           * Counterpart to Solidity's `/` operator. Note: this function uses a
           * `revert` opcode (which leaves remaining gas untouched) while Solidity
           * uses an invalid opcode to revert (consuming all remaining gas).
           *
           * Requirements:
           *
           * - The divisor cannot be zero.
           */
          function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
              require(b > 0, errorMessage);
              return a / b;
          }
          /**
           * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
           * reverting with custom message when dividing by zero.
           *
           * CAUTION: This function is deprecated because it requires allocating memory for the error
           * message unnecessarily. For custom revert reasons use {tryMod}.
           *
           * Counterpart to Solidity's `%` operator. This function uses a `revert`
           * opcode (which leaves remaining gas untouched) while Solidity uses an
           * invalid opcode to revert (consuming all remaining gas).
           *
           * Requirements:
           *
           * - The divisor cannot be zero.
           */
          function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
              require(b > 0, errorMessage);
              return a % b;
          }
      }