Encode a ``message`` for writing into the wire.

        To produce several frames for a given large message use
        :meth:`multi_encode` method.

def encode(self, message, final=True, masking_key=None,
               opcode=None, rsv1=0, rsv2=0, rsv3=0):
        '''Encode a ``message`` for writing into the wire.

        To produce several frames for a given large message use
        :meth:`multi_encode` method.
        '''
        fin = 1 if final else 0
        opcode, masking_key, data = self._info(message, opcode, masking_key)
        return self._encode(data, opcode, masking_key, fin,
                            rsv1, rsv2, rsv3)