code: def sendFragmentStart(self, data):
        
        opcode = BINARY
        if isinstance(data, unicode):
           opcode = TEXT
        self._sendMessage(True, opcode, data)
docs: Send the start of a data fragment stream to a websocket client.
            Subsequent data should be sent using sendFragment().
            A fragment stream is completed when sendFragmentEnd() is called.
  
            If data is a unicode object then the frame is sent as Text.
            If the data is a bytearray object then the frame is sent as Binary.