```\n    function getAccountPrimeDebtBalance(uint16 currencyId, address account) external view override returns (\n        int256 debtBalance\n    ) {\n        mapping(address => mapping(uint256 => BalanceStorage)) storage store = LibStorage.getBalanceStorage();\n        BalanceStorage storage balanceStorage = store[account][currencyId];\n        int256 cashBalance = balanceStorage.cashBalance;\n\n        // Only return cash balances less than zero\n        debtBalance = cashBalance < 0 ? debtBalance : 0;   //<------@audit wrong, Always return 0\n    }\n```\n