// add collateral and debt
ICDPVault(leverParams.vault).modifyCollateralAndDebt(
    leverParams.position,
    address(this),
    address(this),
    toInt256(collateral),
    toInt256(addDebt)
);
return ICDPVault(leverParams.vault).deposit(address(this), addCollateralAmount);
return addCollateralAmount;
