if (_borrowAsset == address(0)) {
        uint256 _returnETH = msg.value.sub(_borrowTokens, 'Insufficient ETH to liquidate');
        if (_returnETH != 0) {
                (bool success, ) = msg.sender.call{value: _returnETH}('');
                require(success, 'Transfer fail');
        }
}
if (_borrowAsset == address(0)) {
        uint256 _returnETH = msg.value.sub(_borrowTokens, 'Insufficient ETH to liquidate');
        
        (bool success, ) = _lender.call{value: _borrowTokens}('');
        require(success, 'liquidate: Transfer failed');
        
        if (_returnETH != 0) {
                (success, ) = msg.sender.call{value: _returnETH}('');
                require(success, 'liquidate: Return transfer failed');
        }
}
