function loanRepayment(
    uint256 _loanId,
    uint256 _principalAmount,
    uint256 _apr,
    uint256,
    uint256 _protocolFee,
    uint256 _startTime
) external override onlyAcceptedCallers {
    uint256 netApr = _netApr(_apr, _protocolFee);
    uint256 interestEarned = _principalAmount.getInterest(netApr, block.timestamp - _startTime);
    uint256 received = _principalAmount + interestEarned;
    uint256 fees = IFeeManager(getFeeManager).processFees(_principalAmount, interestEarned);
    getCollectedFees += fees; // @audit getCollectedFees is never transfer out
    _loanTermination(msg.sender, _loanId, _principalAmount, netApr, interestEarned, received - fees);
}
function processFees(uint256 _principal, uint256 _interest) external view returns (uint256) {
    /// @dev cached
    Fees memory __fees = _fees;
    return _principal.mulDivDown(__fees.managementFee, PRECISION)
        + _interest.mulDivDown(__fees.performanceFee, PRECISION);
}
