code: async def connect(self, host, port=DEFAULT_PORT):
          
          await super().connect(host, port)
          code, info = await self.command(None, "220", "120")
          return info
docs: :py:func:`asyncio.coroutine`
  
          Connect to server.
  
          :param host: host name for connection
          :type host: :py:class:`str`
  
          :param port: port number for connection
          :type port: :py:class:`int`