function decimals() external view returns (uint256);function deposit() external payable;function withdraw(uint256 wad) external;event Deposit(address indexed dst, uint256 wad);event Withdrawal(address indexed src, uint256 wad);function decimals() external view returns (uint256);function deposit() external payable;function withdraw(uint256 wad) external;event Deposit(address indexed dst, uint256 wad);event Withdrawal(address indexed src, uint256 wad);