{"Context.sol":{"content":"pragma solidity ^0.5.0;\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 */\ncontract Context {\n // Empty internal constructor, to prevent people from mistakenly deploying\n // an instance of this contract, which should be used via inheritance.\n constructor () internal { }\n // solhint-disable-previous-line no-empty-blocks\n\n function _msgSender() internal view returns (address payable) {\n return msg.sender;\n }\n\n function _msgData() internal view 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"},"ERC20.sol":{"content":"pragma solidity ^0.5.0;\n\nimport \"./Context.sol\";\nimport \"./IERC20.sol\";\nimport \"./SafeMath.sol\";\n\n/**\n * @dev Implementation of the {IERC20} interface.\n *\n * This implementation is agnostic to the way tokens are created. This means\n * that a supply mechanism has to be added in a derived contract using {_mint}.\n * For a generic mechanism see {ERC20Mintable}.\n *\n * TIP: For a detailed writeup see our guide\n * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How\n * to implement supply mechanisms].\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 ERC20 is Context, IERC20 {\n using SafeMath for uint256;\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 /**\n * @dev See {IERC20-totalSupply}.\n */\n function totalSupply() public view returns (uint256) {\n return _totalSupply;\n }\n\n /**\n * @dev See {IERC20-balanceOf}.\n */\n function balanceOf(address account) public view 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 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 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 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 returns (bool) {\n _transfer(sender, recipient, amount);\n _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, \"ERC20: 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 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 returns (bool) {\n _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, \"ERC20: 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 {\n require(sender != address(0), \"ERC20: transfer from the zero address\");\n require(recipient != address(0), \"ERC20: transfer to the zero address\");\n\n _balances[sender] = _balances[sender].sub(amount, \"ERC20: 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 {\n require(account != address(0), \"ERC20: mint to the zero address\");\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 Destroys `amount` tokens from `account`, reducing the\n * total supply.\n *\n * Emits a {Transfer} event with `to` set to the zero address.\n *\n * Requirements\n *\n * - `account` cannot be the zero address.\n * - `account` must have at least `amount` tokens.\n */\n function _burn(address account, uint256 amount) internal {\n require(account != address(0), \"ERC20: burn from the zero address\");\n\n _balances[account] = _balances[account].sub(amount, \"ERC20: burn amount exceeds balance\");\n _totalSupply = _totalSupply.sub(amount);\n emit Transfer(account, address(0), 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 {\n require(owner != address(0), \"ERC20: approve from the zero address\");\n require(spender != address(0), \"ERC20: approve to the zero address\");\n\n _allowances[owner][spender] = amount;\n emit Approval(owner, spender, amount);\n }\n\n /**\n * @dev Destroys `amount` tokens from `account`.`amount` is then deducted\n * from the caller\u0027s allowance.\n *\n * See {_burn} and {_approve}.\n */\n function _burnFrom(address account, uint256 amount) internal {\n _burn(account, amount);\n _approve(account, _msgSender(), _allowances[account][_msgSender()].sub(amount, \"ERC20: burn amount exceeds allowance\"));\n }\n}\n"},"ERC20Burnable.sol":{"content":"pragma solidity ^0.5.0;\n\nimport \"./Context.sol\";\nimport \"./ERC20.sol\";\n\n/**\n * @dev Extension of {ERC20} that allows token holders to destroy both their own\n * tokens and those that they have an allowance for, in a way that can be\n * recognized off-chain (via event analysis).\n */\ncontract ERC20Burnable is Context, ERC20 {\n /**\n * @dev Destroys `amount` tokens from the caller.\n *\n * See {ERC20-_burn}.\n */\n function burn(uint256 amount) public {\n _burn(_msgSender(), amount);\n }\n\n /**\n * @dev See {ERC20-_burnFrom}.\n */\n function burnFrom(address account, uint256 amount) public {\n _burnFrom(account, amount);\n }\n}\n"},"ERC20Capped.sol":{"content":"pragma solidity ^0.5.0;\n\nimport \"./ERC20Mintable.sol\";\n\n/**\n * @dev Extension of {ERC20Mintable} that adds a cap to the supply of tokens.\n */\ncontract ERC20Capped is ERC20Mintable {\n uint256 private _cap;\n\n /**\n * @dev Sets the value of the `cap`. This value is immutable, it can only be\n * set once during construction.\n */\n constructor (uint256 cap) public {\n require(cap \u003e 0, \"ERC20Capped: cap is 0\");\n _cap = cap;\n }\n\n /**\n * @dev Returns the cap on the token\u0027s total supply.\n */\n function cap() public view returns (uint256) {\n return _cap;\n }\n\n /**\n * @dev See {ERC20Mintable-mint}.\n *\n * Requirements:\n *\n * - `value` must not cause the total supply to go over the cap.\n */\n function _mint(address account, uint256 value) internal {\n require(totalSupply().add(value) \u003c= _cap, \"ERC20Capped: cap exceeded\");\n super._mint(account, value);\n }\n}\n"},"ERC20Detailed.sol":{"content":"pragma solidity ^0.5.0;\n\nimport \"./IERC20.sol\";\n\n/**\n * @dev Optional functions from the ERC20 standard.\n */\ncontract ERC20Detailed is IERC20 {\n string private _name;\n string private _symbol;\n uint8 private _decimals;\n\n /**\n * @dev Sets the values for `name`, `symbol`, and `decimals`. All three of\n * these values are immutable: they can only be set once during\n * construction.\n */\n constructor (string memory name, string memory symbol, uint8 decimals) public {\n _name = name;\n _symbol = symbol;\n _decimals = decimals;\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.\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"},"ERC20Mintable.sol":{"content":"pragma solidity ^0.5.0;\n\nimport \"./ERC20.sol\";\nimport \"./MinterRole.sol\";\n\n/**\n * @dev Extension of {ERC20} that adds a set of accounts with the {MinterRole},\n * which have permission to mint (create) new tokens as they see fit.\n *\n * At construction, the deployer of the contract is the only minter.\n */\ncontract ERC20Mintable is ERC20, MinterRole {\n /**\n * @dev See {ERC20-_mint}.\n *\n * Requirements:\n *\n * - the caller must have the {MinterRole}.\n */\n function mint(address account, uint256 amount) public onlyMinter returns (bool) {\n _mint(account, amount);\n return true;\n }\n}\n"},"ERC20MultiFunctionGenerator.sol":{"content":"pragma solidity \u003e=0.4.21 \u003c0.7.0;\n\nimport \"./ERC20.sol\";\nimport \"./ERC20Detailed.sol\";\nimport \"./ERC20Burnable.sol\";\nimport \"./ERC20Capped.sol\";\nimport \"./ERC20Pausable.sol\";\n \n//Multifunctional ERC20 tokens, can be issued, destroyed, suspended, capped,mint\ncontract ERC20MultiFunction is\n ERC20,\n ERC20Detailed,\n ERC20Burnable,\n ERC20Capped,\n ERC20Pausable\n{\n constructor(\n string memory name, //token name\n string memory symbol, //symbol\n uint8 decimals, \n uint256 totalSupply, \n uint256 cap, //Capped number\n address adminAddress\n ) public ERC20Detailed(name, symbol, decimals) ERC20Capped(cap * (10**uint256(decimals))){\n _mint(adminAddress, totalSupply * (10**uint256(decimals)));\n }\n}\n\n\n\n"},"ERC20Pausable.sol":{"content":"pragma solidity ^0.5.0;\n\nimport \"./ERC20.sol\";\nimport \"./Pausable.sol\";\n\n/**\n * @title Pausable token\n * @dev ERC20 with pausable transfers and allowances.\n *\n * Useful if you want to stop trades until the end of a crowdsale, or have\n * an emergency switch for freezing all token transfers in the event of a large\n * bug.\n */\ncontract ERC20Pausable is ERC20, Pausable {\n function transfer(address to, uint256 value) public whenNotPaused returns (bool) {\n return super.transfer(to, value);\n }\n\n function transferFrom(address from, address to, uint256 value) public whenNotPaused returns (bool) {\n return super.transferFrom(from, to, value);\n }\n\n function approve(address spender, uint256 value) public whenNotPaused returns (bool) {\n return super.approve(spender, value);\n }\n\n function increaseAllowance(address spender, uint256 addedValue) public whenNotPaused returns (bool) {\n return super.increaseAllowance(spender, addedValue);\n }\n\n function decreaseAllowance(address spender, uint256 subtractedValue) public whenNotPaused returns (bool) {\n return super.decreaseAllowance(spender, subtractedValue);\n }\n}\n"},"IERC20.sol":{"content":"pragma solidity ^0.5.0;\n\n/**\n * @dev Interface of the ERC20 standard as defined in the EIP. Does not include\n * the optional functions; to access them see {ERC20Detailed}.\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"},"MinterRole.sol":{"content":"pragma solidity ^0.5.0;\n\nimport \"./Context.sol\";\nimport \"./Roles.sol\";\n\ncontract MinterRole is Context {\n using Roles for Roles.Role;\n\n event MinterAdded(address indexed account);\n event MinterRemoved(address indexed account);\n\n Roles.Role private _minters;\n\n constructor () internal {\n _addMinter(_msgSender());\n }\n\n modifier onlyMinter() {\n require(isMinter(_msgSender()), \"MinterRole: caller does not have the Minter role\");\n _;\n }\n\n function isMinter(address account) public view returns (bool) {\n return _minters.has(account);\n }\n\n function addMinter(address account) public onlyMinter {\n _addMinter(account);\n }\n\n function renounceMinter() public {\n _removeMinter(_msgSender());\n }\n\n function _addMinter(address account) internal {\n _minters.add(account);\n emit MinterAdded(account);\n }\n\n function _removeMinter(address account) internal {\n _minters.remove(account);\n emit MinterRemoved(account);\n }\n}\n"},"Pausable.sol":{"content":"pragma solidity ^0.5.0;\n\nimport \"./Context.sol\";\nimport \"./PauserRole.sol\";\n\n/**\n * @dev Contract module which allows children to implement an emergency stop\n * mechanism that can be triggered by an authorized account.\n *\n * This module is used through inheritance. It will make available the\n * modifiers `whenNotPaused` and `whenPaused`, which can be applied to\n * the functions of your contract. Note that they will not be pausable by\n * simply including this module, only once the modifiers are put in place.\n */\ncontract Pausable is Context, PauserRole {\n /**\n * @dev Emitted when the pause is triggered by a pauser (`account`).\n */\n event Paused(address account);\n\n /**\n * @dev Emitted when the pause is lifted by a pauser (`account`).\n */\n event Unpaused(address account);\n\n bool private _paused;\n\n /**\n * @dev Initializes the contract in unpaused state. Assigns the Pauser role\n * to the deployer.\n */\n constructor () internal {\n _paused = false;\n }\n\n /**\n * @dev Returns true if the contract is paused, and false otherwise.\n */\n function paused() public view returns (bool) {\n return _paused;\n }\n\n /**\n * @dev Modifier to make a function callable only when the contract is not paused.\n */\n modifier whenNotPaused() {\n require(!_paused, \"Pausable: paused\");\n _;\n }\n\n /**\n * @dev Modifier to make a function callable only when the contract is paused.\n */\n modifier whenPaused() {\n require(_paused, \"Pausable: not paused\");\n _;\n }\n\n /**\n * @dev Called by a pauser to pause, triggers stopped state.\n */\n function pause() public onlyPauser whenNotPaused {\n _paused = true;\n emit Paused(_msgSender());\n }\n\n /**\n * @dev Called by a pauser to unpause, returns to normal state.\n */\n function unpause() public onlyPauser whenPaused {\n _paused = false;\n emit Unpaused(_msgSender());\n }\n}\n"},"PauserRole.sol":{"content":"pragma solidity ^0.5.0;\n\nimport \"./Context.sol\";\nimport \"./Roles.sol\";\n\ncontract PauserRole is Context {\n using Roles for Roles.Role;\n\n event PauserAdded(address indexed account);\n event PauserRemoved(address indexed account);\n\n Roles.Role private _pausers;\n\n constructor () internal {\n _addPauser(_msgSender());\n }\n\n modifier onlyPauser() {\n require(isPauser(_msgSender()), \"PauserRole: caller does not have the Pauser role\");\n _;\n }\n\n function isPauser(address account) public view returns (bool) {\n return _pausers.has(account);\n }\n\n function addPauser(address account) public onlyPauser {\n _addPauser(account);\n }\n\n function renouncePauser() public {\n _removePauser(_msgSender());\n }\n\n function _addPauser(address account) internal {\n _pausers.add(account);\n emit PauserAdded(account);\n }\n\n function _removePauser(address account) internal {\n _pausers.remove(account);\n emit PauserRemoved(account);\n }\n}\n"},"Roles.sol":{"content":"pragma solidity ^0.5.0;\n\n/**\n * @title Roles\n * @dev Library for managing addresses assigned to a Role.\n */\nlibrary Roles {\n struct Role {\n mapping (address =\u003e bool) bearer;\n }\n\n /**\n * @dev Give an account access to this role.\n */\n function add(Role storage role, address account) internal {\n require(!has(role, account), \"Roles: account already has role\");\n role.bearer[account] = true;\n }\n\n /**\n * @dev Remove an account\u0027s access to this role.\n */\n function remove(Role storage role, address account) internal {\n require(has(role, account), \"Roles: account does not have role\");\n role.bearer[account] = false;\n }\n\n /**\n * @dev Check if an account has this role.\n * @return bool\n */\n function has(Role storage role, address account) internal view returns (bool) {\n require(account != address(0), \"Roles: account is the zero address\");\n return role.bearer[account];\n }\n}\n"},"SafeMath.sol":{"content":"pragma solidity ^0.5.0;\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 * - 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 * - 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 * - Subtraction cannot overflow.\n *\n * _Available since v2.4.0._\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 * - 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 * - 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 * - The divisor cannot be zero.\n *\n * _Available since v2.4.0._\n */\n function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\n // Solidity only automatically asserts when dividing by 0\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 * - 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 * - The divisor cannot be zero.\n *\n * _Available since v2.4.0._\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"}}