function deposit(address _receiver) external payable returns (uint256);
function previewDeposit(uint256 _assets) external view returns (uint256);
function previewWithdraw(uint256 _shares) external view returns (uint256);
function getExchangeRate() external view returns (uint256);
function staderConfig() external view returns (IStaderConfig);
function totalAssets() external view returns (uint256);