{"AccessControl.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\n\nimport \"./Context.sol\";\nimport \"./Strings.sol\";\nimport \"./ERC165.sol\";\n\n/**\n * @dev External interface of AccessControl declared to support ERC165 detection.\n */\ninterface IAccessControl {\n    function hasRole(bytes32 role, address account) external view returns (bool);\n    function getRoleAdmin(bytes32 role) external view returns (bytes32);\n    function grantRole(bytes32 role, address account) external;\n    function revokeRole(bytes32 role, address account) external;\n    function renounceRole(bytes32 role, address account) external;\n}\n\n/**\n * @dev Contract module that allows children to implement role-based access\n * control mechanisms. This is a lightweight version that doesn\u0027t allow enumerating role\n * members except through off-chain means by accessing the contract event logs. Some\n * applications may benefit from on-chain enumerability, for those cases see\n * {AccessControlEnumerable}.\n *\n * Roles are referred to by their `bytes32` identifier. These should be exposed\n * in the external API and be unique. The best way to achieve this is by\n * using `public constant` hash digests:\n *\n * ```\n * bytes32 public constant MY_ROLE = keccak256(\"MY_ROLE\");\n * ```\n *\n * Roles can be used to represent a set of permissions. To restrict access to a\n * function call, use {hasRole}:\n *\n * ```\n * function foo() public {\n *     require(hasRole(MY_ROLE, msg.sender));\n *     ...\n * }\n * ```\n *\n * Roles can be granted and revoked dynamically via the {grantRole} and\n * {revokeRole} functions. Each role has an associated admin role, and only\n * accounts that have a role\u0027s admin role can call {grantRole} and {revokeRole}.\n *\n * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means\n * that only accounts with this role will be able to grant or revoke other\n * roles. More complex role relationships can be created by using\n * {_setRoleAdmin}.\n *\n * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to\n * grant and revoke this role. Extra precautions should be taken to secure\n * accounts that have been granted it.\n */\nabstract contract AccessControl is Context, IAccessControl, ERC165 {\n    struct RoleData {\n        mapping (address =\u003e bool) members;\n        bytes32 adminRole;\n    }\n\n    mapping (bytes32 =\u003e RoleData) private _roles;\n\n    bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;\n\n    /**\n     * @dev Emitted when `newAdminRole` is set as ``role``\u0027s admin role, replacing `previousAdminRole`\n     *\n     * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite\n     * {RoleAdminChanged} not being emitted signaling this.\n     *\n     * _Available since v3.1._\n     */\n    event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);\n\n    /**\n     * @dev Emitted when `account` is granted `role`.\n     *\n     * `sender` is the account that originated the contract call, an admin role\n     * bearer except when using {_setupRole}.\n     */\n    event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);\n\n    /**\n     * @dev Emitted when `account` is revoked `role`.\n     *\n     * `sender` is the account that originated the contract call:\n     *   - if using `revokeRole`, it is the admin role bearer\n     *   - if using `renounceRole`, it is the role bearer (i.e. `account`)\n     */\n    event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);\n\n    /**\n     * @dev Modifier that checks that an account has a specific role. Reverts\n     * with a standardized message including the required role.\n     *\n     * The format of the revert reason is given by the following regular expression:\n     *\n     *  /^AccessControl: account (0x[0-9a-f]{20}) is missing role (0x[0-9a-f]{32})$/\n     *\n     * _Available since v4.1._\n     */\n    modifier onlyRole(bytes32 role) {\n        _checkRole(role, _msgSender());\n        _;\n    }\n\n    /**\n     * @dev See {IERC165-supportsInterface}.\n     */\n    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {\n        return interfaceId == type(IAccessControl).interfaceId\n            || super.supportsInterface(interfaceId);\n    }\n\n    /**\n     * @dev Returns `true` if `account` has been granted `role`.\n     */\n    function hasRole(bytes32 role, address account) public view override returns (bool) {\n        return _roles[role].members[account];\n    }\n\n    /**\n     * @dev Revert with a standard message if `account` is missing `role`.\n     *\n     * The format of the revert reason is given by the following regular expression:\n     *\n     *  /^AccessControl: account (0x[0-9a-f]{20}) is missing role (0x[0-9a-f]{32})$/\n     */\n    function _checkRole(bytes32 role, address account) internal view {\n        if(!hasRole(role, account)) {\n            revert(string(abi.encodePacked(\n                \"AccessControl: account \",\n                Strings.toHexString(uint160(account), 20),\n                \" is missing role \",\n                Strings.toHexString(uint256(role), 32)\n            )));\n        }\n    }\n\n    /**\n     * @dev Returns the admin role that controls `role`. See {grantRole} and\n     * {revokeRole}.\n     *\n     * To change a role\u0027s admin, use {_setRoleAdmin}.\n     */\n    function getRoleAdmin(bytes32 role) public view override returns (bytes32) {\n        return _roles[role].adminRole;\n    }\n\n    /**\n     * @dev Grants `role` to `account`.\n     *\n     * If `account` had not been already granted `role`, emits a {RoleGranted}\n     * event.\n     *\n     * Requirements:\n     *\n     * - the caller must have ``role``\u0027s admin role.\n     */\n    function grantRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {\n        _grantRole(role, account);\n    }\n\n    /**\n     * @dev Revokes `role` from `account`.\n     *\n     * If `account` had been granted `role`, emits a {RoleRevoked} event.\n     *\n     * Requirements:\n     *\n     * - the caller must have ``role``\u0027s admin role.\n     */\n    function revokeRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {\n        _revokeRole(role, account);\n    }\n\n    /**\n     * @dev Revokes `role` from the calling account.\n     *\n     * Roles are often managed via {grantRole} and {revokeRole}: this function\u0027s\n     * purpose is to provide a mechanism for accounts to lose their privileges\n     * if they are compromised (such as when a trusted device is misplaced).\n     *\n     * If the calling account had been granted `role`, emits a {RoleRevoked}\n     * event.\n     *\n     * Requirements:\n     *\n     * - the caller must be `account`.\n     */\n    function renounceRole(bytes32 role, address account) public virtual override {\n        require(account == _msgSender(), \"AccessControl: can only renounce roles for self\");\n\n        _revokeRole(role, account);\n    }\n\n    /**\n     * @dev Grants `role` to `account`.\n     *\n     * If `account` had not been already granted `role`, emits a {RoleGranted}\n     * event. Note that unlike {grantRole}, this function doesn\u0027t perform any\n     * checks on the calling account.\n     *\n     * [WARNING]\n     * ====\n     * This function should only be called from the constructor when setting\n     * up the initial roles for the system.\n     *\n     * Using this function in any other way is effectively circumventing the admin\n     * system imposed by {AccessControl}.\n     * ====\n     */\n    function _setupRole(bytes32 role, address account) internal virtual {\n        _grantRole(role, account);\n    }\n\n    /**\n     * @dev Sets `adminRole` as ``role``\u0027s admin role.\n     *\n     * Emits a {RoleAdminChanged} event.\n     */\n    function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {\n        emit RoleAdminChanged(role, getRoleAdmin(role), adminRole);\n        _roles[role].adminRole = adminRole;\n    }\n\n    function _grantRole(bytes32 role, address account) private {\n        if (!hasRole(role, account)) {\n            _roles[role].members[account] = true;\n            emit RoleGranted(role, account, _msgSender());\n        }\n    }\n\n    function _revokeRole(bytes32 role, address account) private {\n        if (hasRole(role, account)) {\n            _roles[role].members[account] = false;\n            emit RoleRevoked(role, account, _msgSender());\n        }\n    }\n}\n"},"Address.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\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 on 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        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: value }(data);\n        return _verifyCallResult(success, returndata, errorMessage);\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],\n     * but performing a static call.\n     *\n     * _Available since v3.3._\n     */\n    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {\n        return functionStaticCall(target, data, \"Address: low-level static call failed\");\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],\n     * but performing a static call.\n     *\n     * _Available since v3.3._\n     */\n    function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {\n        require(isContract(target), \"Address: static call to non-contract\");\n\n        // solhint-disable-next-line avoid-low-level-calls\n        (bool success, bytes memory returndata) = target.staticcall(data);\n        return _verifyCallResult(success, returndata, errorMessage);\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],\n     * but performing a delegate call.\n     *\n     * _Available since v3.4._\n     */\n    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {\n        return functionDelegateCall(target, data, \"Address: low-level delegate call failed\");\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],\n     * but performing a delegate call.\n     *\n     * _Available since v3.4._\n     */\n    function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {\n        require(isContract(target), \"Address: delegate call to non-contract\");\n\n        // solhint-disable-next-line avoid-low-level-calls\n        (bool success, bytes memory returndata) = target.delegatecall(data);\n        return _verifyCallResult(success, returndata, errorMessage);\n    }\n\n    function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {\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"},"Arrays.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\n\nimport \"./Math.sol\";\n\n/**\n * @dev Collection of functions related to array types.\n */\nlibrary Arrays {\n   /**\n     * @dev Searches a sorted `array` and returns the first index that contains\n     * a value greater or equal to `element`. If no such index exists (i.e. all\n     * values in the array are strictly less than `element`), the array length is\n     * returned. Time complexity O(log n).\n     *\n     * `array` is expected to be sorted in ascending order, and to contain no\n     * repeated elements.\n     */\n    function findUpperBound(uint256[] storage array, uint256 element) internal view returns (uint256) {\n        if (array.length == 0) {\n            return 0;\n        }\n\n        uint256 low = 0;\n        uint256 high = array.length;\n\n        while (low \u003c high) {\n            uint256 mid = Math.average(low, high);\n\n            // Note that mid will always be strictly less than high (i.e. it will be a valid array index)\n            // because Math.average rounds down (it does integer division with truncation).\n            if (array[mid] \u003e element) {\n                high = mid;\n            } else {\n                low = mid + 1;\n            }\n        }\n\n        // At this point `low` is the exclusive upper bound. We will return the inclusive upper bound.\n        if (low \u003e 0 \u0026\u0026 array[low - 1] == element) {\n            return low - 1;\n        } else {\n            return low;\n        }\n    }\n}\n"},"Context.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\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 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) {\n        return msg.sender;\n    }\n\n    function _msgData() internal view virtual returns (bytes calldata) {\n        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691\n        return msg.data;\n    }\n}\n"},"Counters.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\n\n/**\n * @title Counters\n * @author Matt Condon (@shrugs)\n * @dev Provides counters that can only be incremented or decremented by one. This can be used e.g. to track the number\n * of elements in a mapping, issuing ERC721 ids, or counting request ids.\n *\n * Include with `using Counters for Counters.Counter;`\n */\nlibrary Counters {\n    struct Counter {\n        // This variable should never be directly accessed by users of the library: interactions must be restricted to\n        // the library\u0027s function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add\n        // this feature: see https://github.com/ethereum/solidity/issues/4637\n        uint256 _value; // default: 0\n    }\n\n    function current(Counter storage counter) internal view returns (uint256) {\n        return counter._value;\n    }\n\n    function increment(Counter storage counter) internal {\n        unchecked {\n            counter._value += 1;\n        }\n    }\n\n    function decrement(Counter storage counter) internal {\n        uint256 value = counter._value;\n        require(value \u003e 0, \"Counter: decrement overflow\");\n        unchecked {\n            counter._value = value - 1;\n        }\n    }\n}\n"},"Create2.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Helper to make usage of the `CREATE2` EVM opcode easier and safer.\n * `CREATE2` can be used to compute in advance the address where a smart\n * contract will be deployed, which allows for interesting new mechanisms known\n * as \u0027counterfactual interactions\u0027.\n *\n * See the https://eips.ethereum.org/EIPS/eip-1014#motivation[EIP] for more\n * information.\n */\nlibrary Create2 {\n    /**\n     * @dev Deploys a contract using `CREATE2`. The address where the contract\n     * will be deployed can be known in advance via {computeAddress}.\n     *\n     * The bytecode for a contract can be obtained from Solidity with\n     * `type(contractName).creationCode`.\n     *\n     * Requirements:\n     *\n     * - `bytecode` must not be empty.\n     * - `salt` must have not been used for `bytecode` already.\n     * - the factory must have a balance of at least `amount`.\n     * - if `amount` is non-zero, `bytecode` must have a `payable` constructor.\n     */\n    function deploy(uint256 amount, bytes32 salt, bytes memory bytecode) internal returns (address) {\n        address addr;\n        require(address(this).balance \u003e= amount, \"Create2: insufficient balance\");\n        require(bytecode.length != 0, \"Create2: bytecode length is zero\");\n        // solhint-disable-next-line no-inline-assembly\n        assembly {\n            addr := create2(amount, add(bytecode, 0x20), mload(bytecode), salt)\n        }\n        require(addr != address(0), \"Create2: Failed on deploy\");\n        return addr;\n    }\n\n    /**\n     * @dev Returns the address where a contract will be stored if deployed via {deploy}. Any change in the\n     * `bytecodeHash` or `salt` will result in a new destination address.\n     */\n    function computeAddress(bytes32 salt, bytes32 bytecodeHash) internal view returns (address) {\n        return computeAddress(salt, bytecodeHash, address(this));\n    }\n\n    /**\n     * @dev Returns the address where a contract will be stored if deployed via {deploy} from a contract located at\n     * `deployer`. If `deployer` is this contract\u0027s address, returns the same value as {computeAddress}.\n     */\n    function computeAddress(bytes32 salt, bytes32 bytecodeHash, address deployer) internal pure returns (address) {\n        bytes32 _data = keccak256(\n            abi.encodePacked(bytes1(0xff), deployer, salt, bytecodeHash)\n        );\n        return address(uint160(uint256(_data)));\n    }\n}\n"},"draft-EIP712.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\n\nimport \"./ECDSA.sol\";\n\n/**\n * @dev https://eips.ethereum.org/EIPS/eip-712[EIP 712] is a standard for hashing and signing of typed structured data.\n *\n * The encoding specified in the EIP is very generic, and such a generic implementation in Solidity is not feasible,\n * thus this contract does not implement the encoding itself. Protocols need to implement the type-specific encoding\n * they need in their contracts using a combination of `abi.encode` and `keccak256`.\n *\n * This contract implements the EIP 712 domain separator ({_domainSeparatorV4}) that is used as part of the encoding\n * scheme, and the final step of the encoding to obtain the message digest that is then signed via ECDSA\n * ({_hashTypedDataV4}).\n *\n * The implementation of the domain separator was designed to be as efficient as possible while still properly updating\n * the chain id to protect against replay attacks on an eventual fork of the chain.\n *\n * NOTE: This contract implements the version of the encoding known as \"v4\", as implemented by the JSON RPC method\n * https://docs.metamask.io/guide/signing-data.html[`eth_signTypedDataV4` in MetaMask].\n *\n * _Available since v3.4._\n */\nabstract contract EIP712 {\n    /* solhint-disable var-name-mixedcase */\n    // Cache the domain separator as an immutable value, but also store the chain id that it corresponds to, in order to\n    // invalidate the cached domain separator if the chain id changes.\n    bytes32 private immutable _CACHED_DOMAIN_SEPARATOR;\n    uint256 private immutable _CACHED_CHAIN_ID;\n\n    bytes32 private immutable _HASHED_NAME;\n    bytes32 private immutable _HASHED_VERSION;\n    bytes32 private immutable _TYPE_HASH;\n    /* solhint-enable var-name-mixedcase */\n\n    /**\n     * @dev Initializes the domain separator and parameter caches.\n     *\n     * The meaning of `name` and `version` is specified in\n     * https://eips.ethereum.org/EIPS/eip-712#definition-of-domainseparator[EIP 712]:\n     *\n     * - `name`: the user readable name of the signing domain, i.e. the name of the DApp or the protocol.\n     * - `version`: the current major version of the signing domain.\n     *\n     * NOTE: These parameters cannot be changed except through a xref:learn::upgrading-smart-contracts.adoc[smart\n     * contract upgrade].\n     */\n    constructor(string memory name, string memory version) {\n        bytes32 hashedName = keccak256(bytes(name));\n        bytes32 hashedVersion = keccak256(bytes(version));\n        bytes32 typeHash = keccak256(\"EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)\");\n        _HASHED_NAME = hashedName;\n        _HASHED_VERSION = hashedVersion;\n        _CACHED_CHAIN_ID = block.chainid;\n        _CACHED_DOMAIN_SEPARATOR = _buildDomainSeparator(typeHash, hashedName, hashedVersion);\n        _TYPE_HASH = typeHash;\n    }\n\n    /**\n     * @dev Returns the domain separator for the current chain.\n     */\n    function _domainSeparatorV4() internal view returns (bytes32) {\n        if (block.chainid == _CACHED_CHAIN_ID) {\n            return _CACHED_DOMAIN_SEPARATOR;\n        } else {\n            return _buildDomainSeparator(_TYPE_HASH, _HASHED_NAME, _HASHED_VERSION);\n        }\n    }\n\n    function _buildDomainSeparator(bytes32 typeHash, bytes32 name, bytes32 version) private view returns (bytes32) {\n        return keccak256(\n            abi.encode(\n                typeHash,\n                name,\n                version,\n                block.chainid,\n                address(this)\n            )\n        );\n    }\n\n    /**\n     * @dev Given an already https://eips.ethereum.org/EIPS/eip-712#definition-of-hashstruct[hashed struct], this\n     * function returns the hash of the fully encoded EIP712 message for this domain.\n     *\n     * This hash can be used together with {ECDSA-recover} to obtain the signer of a message. For example:\n     *\n     * ```solidity\n     * bytes32 digest = _hashTypedDataV4(keccak256(abi.encode(\n     *     keccak256(\"Mail(address to,string contents)\"),\n     *     mailTo,\n     *     keccak256(bytes(mailContents))\n     * )));\n     * address signer = ECDSA.recover(digest, signature);\n     * ```\n     */\n    function _hashTypedDataV4(bytes32 structHash) internal view virtual returns (bytes32) {\n        return ECDSA.toTypedDataHash(_domainSeparatorV4(), structHash);\n    }\n}\n"},"draft-ERC20Permit.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\n\nimport \"./draft-IERC20Permit.sol\";\nimport \"./ERC20.sol\";\nimport \"./draft-EIP712.sol\";\nimport \"./ECDSA.sol\";\nimport \"./Counters.sol\";\n\n/**\n * @dev Implementation of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in\n * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].\n *\n * Adds the {permit} method, which can be used to change an account\u0027s ERC20 allowance (see {IERC20-allowance}) by\n * presenting a message signed by the account. By not relying on `{IERC20-approve}`, the token holder account doesn\u0027t\n * need to send a transaction, and thus is not required to hold Ether at all.\n *\n * _Available since v3.4._\n */\nabstract contract ERC20Permit is ERC20, IERC20Permit, EIP712 {\n    using Counters for Counters.Counter;\n\n    mapping (address =\u003e Counters.Counter) private _nonces;\n\n    // solhint-disable-next-line var-name-mixedcase\n    bytes32 private immutable _PERMIT_TYPEHASH = keccak256(\"Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)\");\n\n    /**\n     * @dev Initializes the {EIP712} domain separator using the `name` parameter, and setting `version` to `\"1\"`.\n     *\n     * It\u0027s a good idea to use the same `name` that is defined as the ERC20 token name.\n     */\n    constructor(string memory name) EIP712(name, \"1\") {\n    }\n\n    /**\n     * @dev See {IERC20Permit-permit}.\n     */\n    function permit(address owner, address spender, uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) public virtual override {\n        // solhint-disable-next-line not-rely-on-time\n        require(block.timestamp \u003c= deadline, \"ERC20Permit: expired deadline\");\n\n        bytes32 structHash = keccak256(\n            abi.encode(\n                _PERMIT_TYPEHASH,\n                owner,\n                spender,\n                value,\n                _useNonce(owner),\n                deadline\n            )\n        );\n\n        bytes32 hash = _hashTypedDataV4(structHash);\n\n        address signer = ECDSA.recover(hash, v, r, s);\n        require(signer == owner, \"ERC20Permit: invalid signature\");\n\n        _approve(owner, spender, value);\n    }\n\n    /**\n     * @dev See {IERC20Permit-nonces}.\n     */\n    function nonces(address owner) public view virtual override returns (uint256) {\n        return _nonces[owner].current();\n    }\n\n    /**\n     * @dev See {IERC20Permit-DOMAIN_SEPARATOR}.\n     */\n    // solhint-disable-next-line func-name-mixedcase\n    function DOMAIN_SEPARATOR() external view override returns (bytes32) {\n        return _domainSeparatorV4();\n    }\n\n    /**\n     * @dev \"Consume a nonce\": return the current value and increment.\n     *\n     * _Available since v4.1._\n     */\n    function _useNonce(address owner) internal virtual returns (uint256 current) {\n        Counters.Counter storage nonce = _nonces[owner];\n        current = nonce.current();\n        nonce.increment();\n    }\n}\n"},"draft-IERC20Permit.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in\n * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].\n *\n * Adds the {permit} method, which can be used to change an account\u0027s ERC20 allowance (see {IERC20-allowance}) by\n * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn\u0027t\n * need to send a transaction, and thus is not required to hold Ether at all.\n */\ninterface IERC20Permit {\n    /**\n     * @dev Sets `value` as the allowance of `spender` over ``owner``\u0027s tokens,\n     * given ``owner``\u0027s signed approval.\n     *\n     * IMPORTANT: The same issues {IERC20-approve} has related to transaction\n     * ordering also apply here.\n     *\n     * Emits an {Approval} event.\n     *\n     * Requirements:\n     *\n     * - `spender` cannot be the zero address.\n     * - `deadline` must be a timestamp in the future.\n     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`\n     * over the EIP712-formatted function arguments.\n     * - the signature must use ``owner``\u0027s current nonce (see {nonces}).\n     *\n     * For more information on the signature format, see the\n     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP\n     * section].\n     */\n    function permit(address owner, address spender, uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) external;\n\n    /**\n     * @dev Returns the current nonce for `owner`. This value must be\n     * included whenever a signature is generated for {permit}.\n     *\n     * Every successful call to {permit} increases ``owner``\u0027s nonce by one. This\n     * prevents a signature from being used multiple times.\n     */\n    function nonces(address owner) external view returns (uint256);\n\n    /**\n     * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.\n     */\n    // solhint-disable-next-line func-name-mixedcase\n    function DOMAIN_SEPARATOR() external view returns (bytes32);\n}\n"},"ECDSA.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.\n *\n * These functions can be used to verify that a message was signed by the holder\n * of the private keys of a given address.\n */\nlibrary ECDSA {\n    /**\n     * @dev Returns the address that signed a hashed message (`hash`) with\n     * `signature`. This address can then be used for verification purposes.\n     *\n     * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:\n     * this function rejects them by requiring the `s` value to be in the lower\n     * half order, and the `v` value to be either 27 or 28.\n     *\n     * IMPORTANT: `hash` _must_ be the result of a hash operation for the\n     * verification to be secure: it is possible to craft signatures that\n     * recover to arbitrary addresses for non-hashed data. A safe way to ensure\n     * this is by receiving a hash of the original message (which may otherwise\n     * be too long), and then calling {toEthSignedMessageHash} on it.\n     */\n    function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {\n        // Divide the signature in r, s and v variables\n        bytes32 r;\n        bytes32 s;\n        uint8 v;\n\n        // Check the signature length\n        // - case 65: r,s,v signature (standard)\n        // - case 64: r,vs signature (cf https://eips.ethereum.org/EIPS/eip-2098) _Available since v4.1._\n        if (signature.length == 65) {\n            // ecrecover takes the signature parameters, and the only way to get them\n            // currently is to use assembly.\n            // solhint-disable-next-line no-inline-assembly\n            assembly {\n                r := mload(add(signature, 0x20))\n                s := mload(add(signature, 0x40))\n                v := byte(0, mload(add(signature, 0x60)))\n            }\n        } else if (signature.length == 64) {\n            // ecrecover takes the signature parameters, and the only way to get them\n            // currently is to use assembly.\n            // solhint-disable-next-line no-inline-assembly\n            assembly {\n                let vs := mload(add(signature, 0x40))\n                r := mload(add(signature, 0x20))\n                s := and(vs, 0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff)\n                v := add(shr(255, vs), 27)\n            }\n        } else {\n            revert(\"ECDSA: invalid signature length\");\n        }\n\n        return recover(hash, v, r, s);\n    }\n\n    /**\n     * @dev Overload of {ECDSA-recover} that receives the `v`,\n     * `r` and `s` signature fields separately.\n     */\n    function recover(bytes32 hash, uint8 v, bytes32 r, bytes32 s) internal pure returns (address) {\n        // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature\n        // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines\n        // the valid range for s in (281): 0 \u003c s \u003c secp256k1n ÷ 2 + 1, and for v in (282): v ∈ {27, 28}. Most\n        // signatures from current libraries generate a unique signature with an s-value in the lower half order.\n        //\n        // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value\n        // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or\n        // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept\n        // these malleable signatures as well.\n        require(uint256(s) \u003c= 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0, \"ECDSA: invalid signature \u0027s\u0027 value\");\n        require(v == 27 || v == 28, \"ECDSA: invalid signature \u0027v\u0027 value\");\n\n        // If the signature is valid (and not malleable), return the signer address\n        address signer = ecrecover(hash, v, r, s);\n        require(signer != address(0), \"ECDSA: invalid signature\");\n\n        return signer;\n    }\n\n    /**\n     * @dev Returns an Ethereum Signed Message, created from a `hash`. This\n     * produces hash corresponding to the one signed with the\n     * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]\n     * JSON-RPC method as part of EIP-191.\n     *\n     * See {recover}.\n     */\n    function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32) {\n        // 32 is the length in bytes of hash,\n        // enforced by the type signature above\n        return keccak256(abi.encodePacked(\"\\x19Ethereum Signed Message:\\n32\", hash));\n    }\n\n    /**\n     * @dev Returns an Ethereum Signed Typed Data, created from a\n     * `domainSeparator` and a `structHash`. This produces hash corresponding\n     * to the one signed with the\n     * https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`]\n     * JSON-RPC method as part of EIP-712.\n     *\n     * See {recover}.\n     */\n    function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internal pure returns (bytes32) {\n        return keccak256(abi.encodePacked(\"\\x19\\x01\", domainSeparator, structHash));\n    }\n}\n"},"ERC165.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\n\nimport \"./IERC165.sol\";\n\n/**\n * @dev Implementation of the {IERC165} interface.\n *\n * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check\n * for the additional interface id that will be supported. For example:\n *\n * ```solidity\n * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {\n *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);\n * }\n * ```\n *\n * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.\n */\nabstract contract ERC165 is IERC165 {\n    /**\n     * @dev See {IERC165-supportsInterface}.\n     */\n    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {\n        return interfaceId == type(IERC165).interfaceId;\n    }\n}\n"},"ERC20.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\n\nimport \"./IERC20.sol\";\nimport \"./IERC20Metadata.sol\";\nimport \"./Context.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 {ERC20PresetMinterPauser}.\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, IERC20Metadata {\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;\n    string private _symbol;\n\n    /**\n     * @dev Sets the values for {name} and {symbol}.\n     *\n     * The defaut value of {decimals} is 18. To select a different value for\n     * {decimals} you should overload it.\n     *\n     * All two of these values are immutable: they can only be set once during\n     * construction.\n     */\n    constructor (string memory name_, string memory symbol_) {\n        _name = name_;\n        _symbol = symbol_;\n    }\n\n    /**\n     * @dev Returns the name of the token.\n     */\n    function name() public view virtual override 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 virtual override 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 this function is\n     * overridden;\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 virtual override returns (uint8) {\n        return 18;\n    }\n\n    /**\n     * @dev See {IERC20-totalSupply}.\n     */\n    function totalSupply() public view virtual override returns (uint256) {\n        return _totalSupply;\n    }\n\n    /**\n     * @dev See {IERC20-balanceOf}.\n     */\n    function balanceOf(address account) public view virtual 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     *\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\n        uint256 currentAllowance = _allowances[sender][_msgSender()];\n        require(currentAllowance \u003e= amount, \"ERC20: transfer amount exceeds allowance\");\n        _approve(sender, _msgSender(), currentAllowance - amount);\n\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] + 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        uint256 currentAllowance = _allowances[_msgSender()][spender];\n        require(currentAllowance \u003e= subtractedValue, \"ERC20: decreased allowance below zero\");\n        _approve(_msgSender(), spender, currentAllowance - subtractedValue);\n\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), \"ERC20: transfer from the zero address\");\n        require(recipient != address(0), \"ERC20: transfer to the zero address\");\n\n        _beforeTokenTransfer(sender, recipient, amount);\n\n        uint256 senderBalance = _balances[sender];\n        require(senderBalance \u003e= amount, \"ERC20: transfer amount exceeds balance\");\n        _balances[sender] = senderBalance - amount;\n        _balances[recipient] += amount;\n\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), \"ERC20: mint to the zero address\");\n\n        _beforeTokenTransfer(address(0), account, amount);\n\n        _totalSupply += amount;\n        _balances[account] += 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 virtual {\n        require(account != address(0), \"ERC20: burn from the zero address\");\n\n        _beforeTokenTransfer(account, address(0), amount);\n\n        uint256 accountBalance = _balances[account];\n        require(accountBalance \u003e= amount, \"ERC20: burn amount exceeds balance\");\n        _balances[account] = accountBalance - amount;\n        _totalSupply -= amount;\n\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 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), \"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 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"},"ERC20Burnable.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\n\nimport \"./ERC20.sol\";\nimport \"./Context.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 */\nabstract contract 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 virtual {\n        _burn(_msgSender(), amount);\n    }\n\n    /**\n     * @dev Destroys `amount` tokens from `account`, deducting from the caller\u0027s\n     * allowance.\n     *\n     * See {ERC20-_burn} and {ERC20-allowance}.\n     *\n     * Requirements:\n     *\n     * - the caller must have allowance for ``accounts``\u0027s tokens of at least\n     * `amount`.\n     */\n    function burnFrom(address account, uint256 amount) public virtual {\n        uint256 currentAllowance = allowance(account, _msgSender());\n        require(currentAllowance \u003e= amount, \"ERC20: burn amount exceeds allowance\");\n        _approve(account, _msgSender(), currentAllowance - amount);\n        _burn(account, amount);\n    }\n}\n"},"ERC20Snapshot.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\n\nimport \"./ERC20.sol\";\nimport \"./Arrays.sol\";\nimport \"./Counters.sol\";\n\n/**\n * @dev This contract extends an ERC20 token with a snapshot mechanism. When a snapshot is created, the balances and\n * total supply at the time are recorded for later access.\n *\n * This can be used to safely create mechanisms based on token balances such as trustless dividends or weighted voting.\n * In naive implementations it\u0027s possible to perform a \"double spend\" attack by reusing the same balance from different\n * accounts. By using snapshots to calculate dividends or voting power, those attacks no longer apply. It can also be\n * used to create an efficient ERC20 forking mechanism.\n *\n * Snapshots are created by the internal {_snapshot} function, which will emit the {Snapshot} event and return a\n * snapshot id. To get the total supply at the time of a snapshot, call the function {totalSupplyAt} with the snapshot\n * id. To get the balance of an account at the time of a snapshot, call the {balanceOfAt} function with the snapshot id\n * and the account address.\n *\n * ==== Gas Costs\n *\n * Snapshots are efficient. Snapshot creation is _O(1)_. Retrieval of balances or total supply from a snapshot is _O(log\n * n)_ in the number of snapshots that have been created, although _n_ for a specific account will generally be much\n * smaller since identical balances in subsequent snapshots are stored as a single entry.\n *\n * There is a constant overhead for normal ERC20 transfers due to the additional snapshot bookkeeping. This overhead is\n * only significant for the first transfer that immediately follows a snapshot for a particular account. Subsequent\n * transfers will have normal cost until the next snapshot, and so on.\n */\nabstract contract ERC20Snapshot is ERC20 {\n    // Inspired by Jordi Baylina\u0027s MiniMeToken to record historical balances:\n    // https://github.com/Giveth/minimd/blob/ea04d950eea153a04c51fa510b068b9dded390cb/contracts/MiniMeToken.sol\n\n    using Arrays for uint256[];\n    using Counters for Counters.Counter;\n\n    // Snapshotted values have arrays of ids and the value corresponding to that id. These could be an array of a\n    // Snapshot struct, but that would impede usage of functions that work on an array.\n    struct Snapshots {\n        uint256[] ids;\n        uint256[] values;\n    }\n\n    mapping (address =\u003e Snapshots) private _accountBalanceSnapshots;\n    Snapshots private _totalSupplySnapshots;\n\n    // Snapshot ids increase monotonically, with the first value being 1. An id of 0 is invalid.\n    Counters.Counter private _currentSnapshotId;\n\n    /**\n     * @dev Emitted by {_snapshot} when a snapshot identified by `id` is created.\n     */\n    event Snapshot(uint256 id);\n\n    /**\n     * @dev Creates a new snapshot and returns its snapshot id.\n     *\n     * Emits a {Snapshot} event that contains the same id.\n     *\n     * {_snapshot} is `internal` and you have to decide how to expose it externally. Its usage may be restricted to a\n     * set of accounts, for example using {AccessControl}, or it may be open to the public.\n     *\n     * [WARNING]\n     * ====\n     * While an open way of calling {_snapshot} is required for certain trust minimization mechanisms such as forking,\n     * you must consider that it can potentially be used by attackers in two ways.\n     *\n     * First, it can be used to increase the cost of retrieval of values from snapshots, although it will grow\n     * logarithmically thus rendering this attack ineffective in the long term. Second, it can be used to target\n     * specific accounts and increase the cost of ERC20 transfers for them, in the ways specified in the Gas Costs\n     * section above.\n     *\n     * We haven\u0027t measured the actual numbers; if this is something you\u0027re interested in please reach out to us.\n     * ====\n     */\n    function _snapshot() internal virtual returns (uint256) {\n        _currentSnapshotId.increment();\n\n        uint256 currentId = _currentSnapshotId.current();\n        emit Snapshot(currentId);\n        return currentId;\n    }\n\n    /**\n     * @dev Retrieves the balance of `account` at the time `snapshotId` was created.\n     */\n    function balanceOfAt(address account, uint256 snapshotId) public view virtual returns (uint256) {\n        (bool snapshotted, uint256 value) = _valueAt(snapshotId, _accountBalanceSnapshots[account]);\n\n        return snapshotted ? value : balanceOf(account);\n    }\n\n    /**\n     * @dev Retrieves the total supply at the time `snapshotId` was created.\n     */\n    function totalSupplyAt(uint256 snapshotId) public view virtual returns(uint256) {\n        (bool snapshotted, uint256 value) = _valueAt(snapshotId, _totalSupplySnapshots);\n\n        return snapshotted ? value : totalSupply();\n    }\n\n\n    // Update balance and/or total supply snapshots before the values are modified. This is implemented\n    // in the _beforeTokenTransfer hook, which is executed for _mint, _burn, and _transfer operations.\n    function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual override {\n      super._beforeTokenTransfer(from, to, amount);\n\n      if (from == address(0)) {\n        // mint\n        _updateAccountSnapshot(to);\n        _updateTotalSupplySnapshot();\n      } else if (to == address(0)) {\n        // burn\n        _updateAccountSnapshot(from);\n        _updateTotalSupplySnapshot();\n      } else {\n        // transfer\n        _updateAccountSnapshot(from);\n        _updateAccountSnapshot(to);\n      }\n    }\n\n    function _valueAt(uint256 snapshotId, Snapshots storage snapshots)\n        private view returns (bool, uint256)\n    {\n        require(snapshotId \u003e 0, \"ERC20Snapshot: id is 0\");\n        // solhint-disable-next-line max-line-length\n        require(snapshotId \u003c= _currentSnapshotId.current(), \"ERC20Snapshot: nonexistent id\");\n\n        // When a valid snapshot is queried, there are three possibilities:\n        //  a) The queried value was not modified after the snapshot was taken. Therefore, a snapshot entry was never\n        //  created for this id, and all stored snapshot ids are smaller than the requested one. The value that corresponds\n        //  to this id is the current one.\n        //  b) The queried value was modified after the snapshot was taken. Therefore, there will be an entry with the\n        //  requested id, and its value is the one to return.\n        //  c) More snapshots were created after the requested one, and the queried value was later modified. There will be\n        //  no entry for the requested id: the value that corresponds to it is that of the smallest snapshot id that is\n        //  larger than the requested one.\n        //\n        // In summary, we need to find an element in an array, returning the index of the smallest value that is larger if\n        // it is not found, unless said value doesn\u0027t exist (e.g. when all values are smaller). Arrays.findUpperBound does\n        // exactly this.\n\n        uint256 index = snapshots.ids.findUpperBound(snapshotId);\n\n        if (index == snapshots.ids.length) {\n            return (false, 0);\n        } else {\n            return (true, snapshots.values[index]);\n        }\n    }\n\n    function _updateAccountSnapshot(address account) private {\n        _updateSnapshot(_accountBalanceSnapshots[account], balanceOf(account));\n    }\n\n    function _updateTotalSupplySnapshot() private {\n        _updateSnapshot(_totalSupplySnapshots, totalSupply());\n    }\n\n    function _updateSnapshot(Snapshots storage snapshots, uint256 currentValue) private {\n        uint256 currentId = _currentSnapshotId.current();\n        if (_lastSnapshotId(snapshots.ids) \u003c currentId) {\n            snapshots.ids.push(currentId);\n            snapshots.values.push(currentValue);\n        }\n    }\n\n    function _lastSnapshotId(uint256[] storage ids) private view returns (uint256) {\n        if (ids.length == 0) {\n            return 0;\n        } else {\n            return ids[ids.length - 1];\n        }\n    }\n}\n"},"iagV2_token.sol":{"content":"// SPDX-License-Identifier: MIT\r\npragma solidity ^0.8.0;\r\n\r\nimport \"./ERC20.sol\";\r\nimport \"./ERC20Burnable.sol\";\r\nimport \"./ERC20Snapshot.sol\";\r\nimport \"./AccessControl.sol\";\r\nimport \"./draft-ERC20Permit.sol\";\r\n\r\ncontract IAGON is ERC20, ERC20Burnable, ERC20Snapshot, AccessControl, ERC20Permit {\r\n    bytes32 public constant SNAPSHOT_ROLE = keccak256(\"SNAPSHOT_ROLE\");\r\n\r\n    constructor() ERC20(\"IAGON\", \"IAG\") ERC20Permit(\"IAGON\") {\r\n        _setupRole(DEFAULT_ADMIN_ROLE, msg.sender);\r\n        _setupRole(SNAPSHOT_ROLE, msg.sender);\r\n        _mint(msg.sender, 1000000000 * 10 ** decimals());\r\n    }\r\n\r\n    function snapshot() public {\r\n        require(hasRole(SNAPSHOT_ROLE, msg.sender));\r\n        _snapshot();\r\n    }\r\n\r\n    function _beforeTokenTransfer(address from, address to, uint256 amount)\r\n        internal\r\n        override(ERC20, ERC20Snapshot)\r\n    {\r\n        super._beforeTokenTransfer(from, to, amount);\r\n    }\r\n}"},"IERC165.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Interface of the ERC165 standard, as defined in the\n * https://eips.ethereum.org/EIPS/eip-165[EIP].\n *\n * Implementers can declare support of contract interfaces, which can then be\n * queried by others ({ERC165Checker}).\n *\n * For an implementation, see {ERC165}.\n */\ninterface IERC165 {\n    /**\n     * @dev Returns true if this contract implements the interface defined by\n     * `interfaceId`. See the corresponding\n     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]\n     * to learn more about how these ids are created.\n     *\n     * This function call must use less than 30 000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool);\n}\n"},"IERC20.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\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"},"IERC20Metadata.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\n\nimport \"./IERC20.sol\";\n\n/**\n * @dev Interface for the optional metadata functions from the ERC20 standard.\n *\n * _Available since v4.1._\n */\ninterface IERC20Metadata is IERC20 {\n    /**\n     * @dev Returns the name of the token.\n     */\n    function name() external view returns (string memory);\n\n    /**\n     * @dev Returns the symbol of the token.\n     */\n    function symbol() external view returns (string memory);\n\n    /**\n     * @dev Returns the decimals places of the token.\n     */\n    function decimals() external view returns (uint8);\n}\n"},"Math.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Standard math utilities missing in the Solidity language.\n */\nlibrary Math {\n    /**\n     * @dev Returns the largest of two numbers.\n     */\n    function max(uint256 a, uint256 b) internal pure returns (uint256) {\n        return a \u003e= b ? a : b;\n    }\n\n    /**\n     * @dev Returns the smallest of two numbers.\n     */\n    function min(uint256 a, uint256 b) internal pure returns (uint256) {\n        return a \u003c b ? a : b;\n    }\n\n    /**\n     * @dev Returns the average of two numbers. The result is rounded towards\n     * zero.\n     */\n    function average(uint256 a, uint256 b) internal pure returns (uint256) {\n        // (a + b) / 2 can overflow, so we distribute\n        return (a / 2) + (b / 2) + ((a % 2 + b % 2) / 2);\n    }\n}\n"},"Multicall.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\n\nimport \"./Address.sol\";\n\n/**\n * @dev Provides a function to batch together multiple calls in a single external call.\n *\n * _Available since v4.1._\n */\nabstract contract Multicall {\n    /**\n    * @dev Receives and executes a batch of function calls on this contract.\n    */\n    function multicall(bytes[] calldata data) external returns (bytes[] memory results) {\n        results = new bytes[](data.length);\n        for (uint i = 0; i \u003c data.length; i++) {\n            results[i] = Address.functionDelegateCall(address(this), data[i]);\n        }\n        return results;\n    }\n}\n"},"StorageSlot.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Library for reading and writing primitive types to specific storage slots.\n *\n * Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.\n * This library helps with reading and writing to such slots without the need for inline assembly.\n *\n * The functions in this library return Slot structs that contain a `value` member that can be used to read or write.\n *\n * Example usage to set ERC1967 implementation slot:\n * ```\n * contract ERC1967 {\n *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;\n *\n *     function _getImplementation() internal view returns (address) {\n *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;\n *     }\n *\n *     function _setImplementation(address newImplementation) internal {\n *         require(Address.isContract(newImplementation), \"ERC1967: new implementation is not a contract\");\n *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;\n *     }\n * }\n * ```\n *\n * _Available since v4.1 for `address`, `bool`, `bytes32`, and `uint256`._\n */\nlibrary StorageSlot {\n    struct AddressSlot {\n        address value;\n    }\n\n    struct BooleanSlot {\n        bool value;\n    }\n\n    struct Bytes32Slot {\n        bytes32 value;\n    }\n\n    struct Uint256Slot {\n        uint256 value;\n    }\n\n    /**\n     * @dev Returns an `AddressSlot` with member `value` located at `slot`.\n     */\n    function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {\n        assembly {\n            r.slot := slot\n        }\n    }\n\n    /**\n     * @dev Returns an `BooleanSlot` with member `value` located at `slot`.\n     */\n    function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {\n        assembly {\n            r.slot := slot\n        }\n    }\n\n    /**\n     * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.\n     */\n    function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {\n        assembly {\n            r.slot := slot\n        }\n    }\n\n    /**\n     * @dev Returns an `Uint256Slot` with member `value` located at `slot`.\n     */\n    function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {\n        assembly {\n            r.slot := slot\n        }\n    }\n}\n"},"Strings.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\n\n/**\n * @dev String operations.\n */\nlibrary Strings {\n    bytes16 private constant alphabet = \"0123456789abcdef\";\n\n    /**\n     * @dev Converts a `uint256` to its ASCII `string` decimal representation.\n     */\n    function toString(uint256 value) internal pure returns (string memory) {\n        // Inspired by OraclizeAPI\u0027s implementation - MIT licence\n        // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol\n\n        if (value == 0) {\n            return \"0\";\n        }\n        uint256 temp = value;\n        uint256 digits;\n        while (temp != 0) {\n            digits++;\n            temp /= 10;\n        }\n        bytes memory buffer = new bytes(digits);\n        while (value != 0) {\n            digits -= 1;\n            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));\n            value /= 10;\n        }\n        return string(buffer);\n    }\n\n    /**\n     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.\n     */\n    function toHexString(uint256 value) internal pure returns (string memory) {\n        if (value == 0) {\n            return \"0x00\";\n        }\n        uint256 temp = value;\n        uint256 length = 0;\n        while (temp != 0) {\n            length++;\n            temp \u003e\u003e= 8;\n        }\n        return toHexString(value, length);\n    }\n\n    /**\n     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.\n     */\n    function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {\n        bytes memory buffer = new bytes(2 * length + 2);\n        buffer[0] = \"0\";\n        buffer[1] = \"x\";\n        for (uint256 i = 2 * length + 1; i \u003e 1; --i) {\n            buffer[i] = alphabet[value \u0026 0xf];\n            value \u003e\u003e= 4;\n        }\n        require(value == 0, \"Strings: hex length insufficient\");\n        return string(buffer);\n    }\n\n}\n"}}