```\n    function trackVaultFee(address vault, uint256 feeAmount) external {\n        // Check sender:\n        IDVP dvp = IDVP(msg.sender);\n        if (vault != dvp.vault()) {\n            revert WrongVault();\n        }\n\n        vaultFeeAmounts[vault] += feeAmount;\n\n        emit TransferVaultFee(vault, feeAmount);\n    }\n```\n