'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.'

def setLineMode(self, extra=''):

    self.line_mode = 1
    if extra:
        return self.dataReceived(extra)
