def setLineMode(self, extra=b''):
        """
        Sets the line-mode of this receiver.

        If you are calling this from a rawDataReceived callback,
        you can pass in extra unhandled data, and that data will
        be parsed for lines.  Further data received will be sent
        to lineReceived rather than rawDataReceived.

        Do not pass extra data if calling this function from
        within a lineReceived callback.
        """
        self.line_mode = 1
        if extra:
            return self.dataReceived(extra)

        Sets the line-mode of this receiver.

        If you are calling this from a rawDataReceived callback,
        you can pass in extra unhandled data, and that data will
        be parsed for lines.  Further data received will be sent
        to lineReceived rather than rawDataReceived.

        Do not pass extra data if calling this function from
        within a lineReceived callback.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/protocols/basic.py