File: CDPVault.sol
function deposit(address to, uint256 amount) external whenNotPaused returns (uint256 tokenAmount) {
        tokenAmount = wdiv(amount, tokenScale);
        int256 deltaCollateral = toInt256(tokenAmount);
@>        modifyCollateralAndDebt({
            owner: to,
            collateralizer: msg.sender,
            creditor: msg.sender,
            deltaCollateral: deltaCollateral,
            deltaDebt: 0
        });
    }

function withdraw(address to, uint256 amount) external whenNotPaused returns (uint256 tokenAmount) {
        tokenAmount = wdiv(amount, tokenScale);
        int256 deltaCollateral = -toInt256(tokenAmount);
@>        modifyCollateralAndDebt({
            owner: to,
            collateralizer: msg.sender,
            creditor: msg.sender,
            deltaCollateral: deltaCollateral,
            deltaDebt: 0
        });
    }

 function modifyCollateralAndDebt(
        address owner,
        address collateralizer,
        address creditor,
        int256 deltaCollateral,
        int256 deltaDebt
    ) public {
...

  }
