code: def send(self, data, opcode=ABNF.OPCODE_TEXT):
          
  
          if not self.sock or self.sock.send(data, opcode) == 0:
              raise WebSocketConnectionClosedException(
                  "Connection is already closed.")
docs: send message.
          data: message to send. If you set opcode to OPCODE_TEXT,
                data must be utf-8 string or unicode.
          opcode: operation code of data. default is OPCODE_TEXT.