function concatStorage(bytes _preBytes, bytes _postBytes) internalfunction equalStorage(bytes _preBytes, bytes _postBytes) internal view returns (bool)function concat(bytes _preBytes, bytes _postBytes) internal pure returns (bytes)function slice(bytes _bytes, uint256 _start, uint256 _length) internal pure returns (bytes res)function toAddress(bytes _bytes, uint256 _start) internal pure returns (address)function toUint8(bytes _bytes, uint256 _start) internal pure returns (uint8)function toUint(bytes _bytes, uint256 _start) internal pure returns (uint256)function equal(bytes _preBytes, bytes _postBytes) internal pure returns (bool)function toBytes32(bytes _source) internal pure returns (bytes32 result)function keccak256Slice(bytes _bytes, uint256 _start, uint256 _length) internal pure returns (bytes32 result)