    event Mint(
        string indexed order_id,
        address indexed benefactor,
        address indexed beneficiary,
        address minter,
        address collateral_asset,
L17:    uint256 collateral_amount,
        uint256 ustb_amount
    );
        emit Mint(
            order.order_id,
            order.benefactor,
            order.beneficiary,
            msg.sender,
            order.collateral_asset,
L251:       order.collateral_amount,
            order.ustb_amount
        );
