{"Address.sol":{"content":"// SPDX-License-Identifier: MIT\r\n\r\npragma solidity ^0.6.2;\r\n\r\n/**\r\n * @dev Collection of functions related to the address type\r\n */\r\nlibrary Address {\r\n    /**\r\n     * @dev Returns true if `account` is a contract.\r\n     *\r\n     * [IMPORTANT]\r\n     * ====\r\n     * It is unsafe to assume that an address for which this function returns\r\n     * false is an externally-owned account (EOA) and not a contract.\r\n     *\r\n     * Among others, `isContract` will return false for the following\r\n     * types of addresses:\r\n     *\r\n     *  - an externally-owned account\r\n     *  - a contract in construction\r\n     *  - an address where a contract will be created\r\n     *  - an address where a contract lived, but was destroyed\r\n     * ====\r\n     */\r\n    function isContract(address account) internal view returns (bool) {\r\n        // According to EIP-1052, 0x0 is the value returned for not-yet created accounts\r\n        // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned\r\n        // for accounts without code, i.e. `keccak256(\u0027\u0027)`\r\n        bytes32 codehash;\r\n        bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;\r\n        // solhint-disable-next-line no-inline-assembly\r\n        assembly { codehash := extcodehash(account) }\r\n        return (codehash != accountHash \u0026\u0026 codehash != 0x0);\r\n    }\r\n\r\n    /**\r\n     * @dev Replacement for Solidity\u0027s `transfer`: sends `amount` wei to\r\n     * `recipient`, forwarding all available gas and reverting on errors.\r\n     *\r\n     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost\r\n     * of certain opcodes, possibly making contracts go over the 2300 gas limit\r\n     * imposed by `transfer`, making them unable to receive funds via\r\n     * `transfer`. {sendValue} removes this limitation.\r\n     *\r\n     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].\r\n     *\r\n     * IMPORTANT: because control is transferred to `recipient`, care must be\r\n     * taken to not create reentrancy vulnerabilities. Consider using\r\n     * {ReentrancyGuard} or the\r\n     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].\r\n     */\r\n    function sendValue(address payable recipient, uint256 amount) internal {\r\n        require(address(this).balance \u003e= amount, \"Address: insufficient balance\");\r\n\r\n        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value\r\n        (bool success, ) = recipient.call{ value: amount }(\"\");\r\n        require(success, \"Address: unable to send value, recipient may have reverted\");\r\n    }\r\n}\r\n"},"Context.sol":{"content":"// SPDX-License-Identifier: MIT\r\n\r\npragma solidity ^0.6.0;\r\n\r\n/*\r\n * @dev Provides information about the current execution context, including the\r\n * sender of the transaction and its data. While these are generally available\r\n * via msg.sender and msg.data, they should not be accessed in such a direct\r\n * manner, since when dealing with GSN meta-transactions the account sending and\r\n * paying for execution may not be the actual sender (as far as an application\r\n * is concerned).\r\n *\r\n * This contract is only required for intermediate, library-like contracts.\r\n */\r\nabstract contract Context {\r\n    function _msgSender() internal view virtual returns (address payable) {\r\n        return msg.sender;\r\n    }\r\n\r\n    function _msgData() internal view virtual returns (bytes memory) {\r\n        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691\r\n        return msg.data;\r\n    }\r\n}\r\n"},"ERC20.sol":{"content":"// SPDX-License-Identifier: MIT\r\n\r\npragma solidity ^0.6.0;\r\n\r\nimport \"./Context.sol\";\r\nimport \"./IERC20.sol\";\r\nimport \"./SafeMath.sol\";\r\nimport \"./Address.sol\";\r\n\r\n/**\r\n * @dev Implementation of the {IERC20} interface.\r\n *\r\n * This implementation is agnostic to the way tokens are created. This means\r\n * that a supply mechanism has to be added in a derived contract using {_mint}.\r\n * For a generic mechanism see {ERC20MinterPauser}.\r\n *\r\n * TIP: For a detailed writeup see our guide\r\n * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How\r\n * to implement supply mechanisms].\r\n *\r\n * We have followed general OpenZeppelin guidelines: functions revert instead\r\n * of returning `false` on failure. This behavior is nonetheless conventional\r\n * and does not conflict with the expectations of ERC20 applications.\r\n *\r\n * Additionally, an {Approval} event is emitted on calls to {transferFrom}.\r\n * This allows applications to reconstruct the allowance for all accounts just\r\n * by listening to said events. Other implementations of the EIP may not emit\r\n * these events, as it isn\u0027t required by the specification.\r\n *\r\n * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}\r\n * functions have been added to mitigate the well-known issues around setting\r\n * allowances. See {IERC20-approve}.\r\n */\r\ncontract ERC20 is Context, IERC20 {\r\n    using SafeMath for uint256;\r\n    using Address for address;\r\n\r\n    mapping (address =\u003e uint256) private _balances;\r\n\r\n    mapping (address =\u003e mapping (address =\u003e uint256)) private _allowances;\r\n\r\n    uint256 private _totalSupply;\r\n\r\n    string private _name;\r\n    string private _symbol;\r\n    uint8 private _decimals;\r\n\r\n    /**\r\n     * @dev Sets the values for {name} and {symbol}, initializes {decimals} with\r\n     * a default value of 18.\r\n     *\r\n     * To select a different value for {decimals}, use {_setupDecimals}.\r\n     *\r\n     * All three of these values are immutable: they can only be set once during\r\n     * construction.\r\n     */\r\n    constructor (string memory name, string memory symbol) public {\r\n        _name = name;\r\n        _symbol = symbol;\r\n        _decimals = 18;\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the name of the token.\r\n     */\r\n    function name() public view returns (string memory) {\r\n        return _name;\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the symbol of the token, usually a shorter version of the\r\n     * name.\r\n     */\r\n    function symbol() public view returns (string memory) {\r\n        return _symbol;\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the number of decimals used to get its user representation.\r\n     * For example, if `decimals` equals `2`, a balance of `505` tokens should\r\n     * be displayed to a user as `5,05` (`505 / 10 ** 2`).\r\n     *\r\n     * Tokens usually opt for a value of 18, imitating the relationship between\r\n     * Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is\r\n     * called.\r\n     *\r\n     * NOTE: This information is only used for _display_ purposes: it in\r\n     * no way affects any of the arithmetic of the contract, including\r\n     * {IERC20-balanceOf} and {IERC20-transfer}.\r\n     */\r\n    function decimals() public view returns (uint8) {\r\n        return _decimals;\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC20-totalSupply}.\r\n     */\r\n    function totalSupply() public view override returns (uint256) {\r\n        return _totalSupply;\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC20-balanceOf}.\r\n     */\r\n    function balanceOf(address account) public view override returns (uint256) {\r\n        return _balances[account];\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC20-transfer}.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `recipient` cannot be the zero address.\r\n     * - the caller must have a balance of at least `amount`.\r\n     */\r\n    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {\r\n        _transfer(_msgSender(), recipient, amount);\r\n        return true;\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC20-allowance}.\r\n     */\r\n    function allowance(address owner, address spender) public view virtual override returns (uint256) {\r\n        return _allowances[owner][spender];\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC20-approve}.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `spender` cannot be the zero address.\r\n     */\r\n    function approve(address spender, uint256 amount) public virtual override returns (bool) {\r\n        _approve(_msgSender(), spender, amount);\r\n        return true;\r\n    }\r\n\r\n    /**\r\n     * @dev See {IERC20-transferFrom}.\r\n     *\r\n     * Emits an {Approval} event indicating the updated allowance. This is not\r\n     * required by the EIP. See the note at the beginning of {ERC20};\r\n     *\r\n     * Requirements:\r\n     * - `sender` and `recipient` cannot be the zero address.\r\n     * - `sender` must have a balance of at least `amount`.\r\n     * - the caller must have allowance for ``sender``\u0027s tokens of at least\r\n     * `amount`.\r\n     */\r\n    function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {\r\n        _transfer(sender, recipient, amount);\r\n        _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, \"ERC20: transfer amount exceeds allowance\"));\r\n        return true;\r\n    }\r\n\r\n    /**\r\n     * @dev Atomically increases the allowance granted to `spender` by the caller.\r\n     *\r\n     * This is an alternative to {approve} that can be used as a mitigation for\r\n     * problems described in {IERC20-approve}.\r\n     *\r\n     * Emits an {Approval} event indicating the updated allowance.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `spender` cannot be the zero address.\r\n     */\r\n    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {\r\n        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));\r\n        return true;\r\n    }\r\n\r\n    /**\r\n     * @dev Atomically decreases the allowance granted to `spender` by the caller.\r\n     *\r\n     * This is an alternative to {approve} that can be used as a mitigation for\r\n     * problems described in {IERC20-approve}.\r\n     *\r\n     * Emits an {Approval} event indicating the updated allowance.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `spender` cannot be the zero address.\r\n     * - `spender` must have allowance for the caller of at least\r\n     * `subtractedValue`.\r\n     */\r\n    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {\r\n        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, \"ERC20: decreased allowance below zero\"));\r\n        return true;\r\n    }\r\n\r\n    /**\r\n     * @dev Moves tokens `amount` from `sender` to `recipient`.\r\n     *\r\n     * This is internal function is equivalent to {transfer}, and can be used to\r\n     * e.g. implement automatic token fees, slashing mechanisms, etc.\r\n     *\r\n     * Emits a {Transfer} event.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `sender` cannot be the zero address.\r\n     * - `recipient` cannot be the zero address.\r\n     * - `sender` must have a balance of at least `amount`.\r\n     */\r\n    function _transfer(address sender, address recipient, uint256 amount) internal virtual {\r\n        require(sender != address(0), \"ERC20: transfer from the zero address\");\r\n        require(recipient != address(0), \"ERC20: transfer to the zero address\");\r\n\r\n        _beforeTokenTransfer(sender, recipient, amount);\r\n\r\n        _balances[sender] = _balances[sender].sub(amount, \"ERC20: transfer amount exceeds balance\");\r\n        _balances[recipient] = _balances[recipient].add(amount);\r\n        emit Transfer(sender, recipient, amount);\r\n    }\r\n\r\n    /** @dev Creates `amount` tokens and assigns them to `account`, increasing\r\n     * the total supply.\r\n     *\r\n     * Emits a {Transfer} event with `from` set to the zero address.\r\n     *\r\n     * Requirements\r\n     *\r\n     * - `to` cannot be the zero address.\r\n     */\r\n    function _mint(address account, uint256 amount) internal virtual {\r\n        require(account != address(0), \"ERC20: mint to the zero address\");\r\n\r\n        _beforeTokenTransfer(address(0), account, amount);\r\n\r\n        _totalSupply = _totalSupply.add(amount);\r\n        _balances[account] = _balances[account].add(amount);\r\n        emit Transfer(address(0), account, amount);\r\n    }\r\n\r\n    /**\r\n     * @dev Destroys `amount` tokens from `account`, reducing the\r\n     * total supply.\r\n     *\r\n     * Emits a {Transfer} event with `to` set to the zero address.\r\n     *\r\n     * Requirements\r\n     *\r\n     * - `account` cannot be the zero address.\r\n     * - `account` must have at least `amount` tokens.\r\n     */\r\n    function _burn(address account, uint256 amount) internal virtual {\r\n        require(account != address(0), \"ERC20: burn from the zero address\");\r\n\r\n        _beforeTokenTransfer(account, address(0), amount);\r\n\r\n        _balances[account] = _balances[account].sub(amount, \"ERC20: burn amount exceeds balance\");\r\n        _totalSupply = _totalSupply.sub(amount);\r\n        emit Transfer(account, address(0), amount);\r\n    }\r\n\r\n    /**\r\n     * @dev Sets `amount` as the allowance of `spender` over the `owner`s tokens.\r\n     *\r\n     * This is internal function is equivalent to `approve`, and can be used to\r\n     * e.g. set automatic allowances for certain subsystems, etc.\r\n     *\r\n     * Emits an {Approval} event.\r\n     *\r\n     * Requirements:\r\n     *\r\n     * - `owner` cannot be the zero address.\r\n     * - `spender` cannot be the zero address.\r\n     */\r\n    function _approve(address owner, address spender, uint256 amount) internal virtual {\r\n        require(owner != address(0), \"ERC20: approve from the zero address\");\r\n        require(spender != address(0), \"ERC20: approve to the zero address\");\r\n\r\n        _allowances[owner][spender] = amount;\r\n        emit Approval(owner, spender, amount);\r\n    }\r\n\r\n    /**\r\n     * @dev Sets {decimals} to a value other than the default one of 18.\r\n     *\r\n     * WARNING: This function should only be called from the constructor. Most\r\n     * applications that interact with token contracts will not expect\r\n     * {decimals} to ever change, and may work incorrectly if it does.\r\n     */\r\n    function _setupDecimals(uint8 decimals_) internal {\r\n        _decimals = decimals_;\r\n    }\r\n\r\n    /**\r\n     * @dev Hook that is called before any transfer of tokens. This includes\r\n     * minting and burning.\r\n     *\r\n     * Calling conditions:\r\n     *\r\n     * - when `from` and `to` are both non-zero, `amount` of ``from``\u0027s tokens\r\n     * will be to transferred to `to`.\r\n     * - when `from` is zero, `amount` tokens will be minted for `to`.\r\n     * - when `to` is zero, `amount` of ``from``\u0027s tokens will be burned.\r\n     * - `from` and `to` are never both zero.\r\n     *\r\n     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].\r\n     */\r\n    function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual { }\r\n\t\r\n}\r\n"},"IERC20.sol":{"content":"// SPDX-License-Identifier: MIT\r\n\r\npragma solidity ^0.6.0;\r\n\r\n/**\r\n * @dev Interface of the ERC20 standard as defined in the EIP.\r\n */\r\ninterface IERC20 {\r\n    /**\r\n     * @dev Returns the amount of tokens in existence.\r\n     */\r\n    function totalSupply() external view returns (uint256);\r\n\r\n    /**\r\n     * @dev Returns the amount of tokens owned by `account`.\r\n     */\r\n    function balanceOf(address account) external view returns (uint256);\r\n\r\n    /**\r\n     * @dev Moves `amount` tokens from the caller\u0027s account to `recipient`.\r\n     *\r\n     * Returns a boolean value indicating whether the operation succeeded.\r\n     *\r\n     * Emits a {Transfer} event.\r\n     */\r\n    function transfer(address recipient, uint256 amount) external returns (bool);\r\n\r\n    /**\r\n     * @dev Returns the remaining number of tokens that `spender` will be\r\n     * allowed to spend on behalf of `owner` through {transferFrom}. This is\r\n     * zero by default.\r\n     *\r\n     * This value changes when {approve} or {transferFrom} are called.\r\n     */\r\n    function allowance(address owner, address spender) external view returns (uint256);\r\n\r\n    /**\r\n     * @dev Sets `amount` as the allowance of `spender` over the caller\u0027s tokens.\r\n     *\r\n     * Returns a boolean value indicating whether the operation succeeded.\r\n     *\r\n     * IMPORTANT: Beware that changing an allowance with this method brings the risk\r\n     * that someone may use both the old and the new allowance by unfortunate\r\n     * transaction ordering. One possible solution to mitigate this race\r\n     * condition is to first reduce the spender\u0027s allowance to 0 and set the\r\n     * desired value afterwards:\r\n     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729\r\n     *\r\n     * Emits an {Approval} event.\r\n     */\r\n    function approve(address spender, uint256 amount) external returns (bool);\r\n\r\n    /**\r\n     * @dev Moves `amount` tokens from `sender` to `recipient` using the\r\n     * allowance mechanism. `amount` is then deducted from the caller\u0027s\r\n     * allowance.\r\n     *\r\n     * Returns a boolean value indicating whether the operation succeeded.\r\n     *\r\n     * Emits a {Transfer} event.\r\n     */\r\n    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);\r\n\r\n    /**\r\n     * @dev Emitted when `value` tokens are moved from one account (`from`) to\r\n     * another (`to`).\r\n     *\r\n     * Note that `value` may be zero.\r\n     */\r\n    event Transfer(address indexed from, address indexed to, uint256 value);\r\n\r\n    /**\r\n     * @dev Emitted when the allowance of a `spender` for an `owner` is set by\r\n     * a call to {approve}. `value` is the new allowance.\r\n     */\r\n    event Approval(address indexed owner, address indexed spender, uint256 value);\r\n}\r\n"},"MSVToken.sol":{"content":"pragma solidity ^0.6.0;\r\n\r\nimport \"./ERC20.sol\";\r\n\r\ncontract MSVToken is ERC20{\r\n\r\n    address private minerContractAddr = 0x21031603E69468f439a83f5c4eB893C03c3f866E;\r\n    \r\n    address private nodeLockupContractAddr = 0xcC10ECe0c89aD831A64Db614D90Bc0D8A3cBec1c;\r\n    \r\n    address private ecologicalLockupContractAddr = 0xFC932C3f9366B3ad6143EfB2651324d7967D8001;\r\n    \r\n    address private msvTeamAddr = 0xD48d16c0c842698726d7AF349641bFefB340F6b9;\r\n    \r\n\tconstructor() ERC20(\"MSV Token\",\"MSV\") public {\r\n\t\tuint8 decimals = 18;\r\n\t\t\r\n\t\tuint256 minerSupply = 20000000 * 10 ** uint256(decimals);\r\n\t\tuint256 nodeSupply = 200000 * 10 ** uint256(decimals);\r\n\t\tuint256 ecologicalSupply = 300000 * 10 ** uint256(decimals);\r\n\t\tuint256 teamSupply = 500000 * 10 ** uint256(decimals);\r\n\t\t\r\n\t\t_setupDecimals(decimals);\r\n\t\t_mint(minerContractAddr, minerSupply);\r\n\t\t_mint(nodeLockupContractAddr, nodeSupply);\r\n\t\t_mint(ecologicalLockupContractAddr, ecologicalSupply);\r\n\t\t_mint(msvTeamAddr, teamSupply);\r\n\t}\r\n\t\r\n\tfunction burn(uint256 amount) public returns (bool) {\r\n        _burn(msg.sender, amount);\r\n        return true;\r\n    }\r\n\r\n}"},"SafeMath.sol":{"content":"// SPDX-License-Identifier: MIT\r\n\r\npragma solidity ^0.6.0;\r\n\r\n/**\r\n * @dev Wrappers over Solidity\u0027s arithmetic operations with added overflow\r\n * checks.\r\n *\r\n * Arithmetic operations in Solidity wrap on overflow. This can easily result\r\n * in bugs, because programmers usually assume that an overflow raises an\r\n * error, which is the standard behavior in high level programming languages.\r\n * `SafeMath` restores this intuition by reverting the transaction when an\r\n * operation overflows.\r\n *\r\n * Using this library instead of the unchecked operations eliminates an entire\r\n * class of bugs, so it\u0027s recommended to use it always.\r\n */\r\nlibrary SafeMath {\r\n    /**\r\n     * @dev Returns the addition of two unsigned integers, reverting on\r\n     * overflow.\r\n     *\r\n     * Counterpart to Solidity\u0027s `+` operator.\r\n     *\r\n     * Requirements:\r\n     * - Addition cannot overflow.\r\n     */\r\n    function add(uint256 a, uint256 b) internal pure returns (uint256) {\r\n        uint256 c = a + b;\r\n        require(c \u003e= a, \"SafeMath: addition overflow\");\r\n\r\n        return c;\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the subtraction of two unsigned integers, reverting on\r\n     * overflow (when the result is negative).\r\n     *\r\n     * Counterpart to Solidity\u0027s `-` operator.\r\n     *\r\n     * Requirements:\r\n     * - Subtraction cannot overflow.\r\n     */\r\n    function sub(uint256 a, uint256 b) internal pure returns (uint256) {\r\n        return sub(a, b, \"SafeMath: subtraction overflow\");\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on\r\n     * overflow (when the result is negative).\r\n     *\r\n     * Counterpart to Solidity\u0027s `-` operator.\r\n     *\r\n     * Requirements:\r\n     * - Subtraction cannot overflow.\r\n     */\r\n    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\r\n        require(b \u003c= a, errorMessage);\r\n        uint256 c = a - b;\r\n\r\n        return c;\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the multiplication of two unsigned integers, reverting on\r\n     * overflow.\r\n     *\r\n     * Counterpart to Solidity\u0027s `*` operator.\r\n     *\r\n     * Requirements:\r\n     * - Multiplication cannot overflow.\r\n     */\r\n    function mul(uint256 a, uint256 b) internal pure returns (uint256) {\r\n        // Gas optimization: this is cheaper than requiring \u0027a\u0027 not being zero, but the\r\n        // benefit is lost if \u0027b\u0027 is also tested.\r\n        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522\r\n        if (a == 0) {\r\n            return 0;\r\n        }\r\n\r\n        uint256 c = a * b;\r\n        require(c / a == b, \"SafeMath: multiplication overflow\");\r\n\r\n        return c;\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the integer division of two unsigned integers. Reverts on\r\n     * division by zero. The result is rounded towards zero.\r\n     *\r\n     * Counterpart to Solidity\u0027s `/` operator. Note: this function uses a\r\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\r\n     * uses an invalid opcode to revert (consuming all remaining gas).\r\n     *\r\n     * Requirements:\r\n     * - The divisor cannot be zero.\r\n     */\r\n    function div(uint256 a, uint256 b) internal pure returns (uint256) {\r\n        return div(a, b, \"SafeMath: division by zero\");\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the integer division of two unsigned integers. Reverts with custom message on\r\n     * division by zero. The result is rounded towards zero.\r\n     *\r\n     * Counterpart to Solidity\u0027s `/` operator. Note: this function uses a\r\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\r\n     * uses an invalid opcode to revert (consuming all remaining gas).\r\n     *\r\n     * Requirements:\r\n     * - The divisor cannot be zero.\r\n     */\r\n    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\r\n        require(b \u003e 0, errorMessage);\r\n        uint256 c = a / b;\r\n        // assert(a == b * c + a % b); // There is no case in which this doesn\u0027t hold\r\n\r\n        return c;\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\r\n     * Reverts when dividing by zero.\r\n     *\r\n     * Counterpart to Solidity\u0027s `%` operator. This function uses a `revert`\r\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\r\n     * invalid opcode to revert (consuming all remaining gas).\r\n     *\r\n     * Requirements:\r\n     * - The divisor cannot be zero.\r\n     */\r\n    function mod(uint256 a, uint256 b) internal pure returns (uint256) {\r\n        return mod(a, b, \"SafeMath: modulo by zero\");\r\n    }\r\n\r\n    /**\r\n     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\r\n     * Reverts with custom message when dividing by zero.\r\n     *\r\n     * Counterpart to Solidity\u0027s `%` operator. This function uses a `revert`\r\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\r\n     * invalid opcode to revert (consuming all remaining gas).\r\n     *\r\n     * Requirements:\r\n     * - The divisor cannot be zero.\r\n     */\r\n    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\r\n        require(b != 0, errorMessage);\r\n        return a % b;\r\n    }\r\n}\r\n"}}