code: async def parse_command(self, stream):
          
          line = await stream.readline()
          if not line:
              raise ConnectionResetError
          s = line.decode(encoding=self.encoding).rstrip()
          logger.info(s)
          cmd, _, rest = s.partition(" ")
          return cmd.lower(), rest
docs: :py:func:`asyncio.coroutine`
  
          Complex method for getting command.
  
          :param stream: connection steram
          :type stream: :py:class:`asyncio.StreamIO`
  
          :return: (code, rest)
          :rtype: (:py:class:`str`, :py:class:`str`)