code: def client_connected(
          self, reader: asyncio.StreamReader, writer: asyncio.StreamWriter
      ) -> None:
          
          self.reader = reader
          self.writer = writer
docs: Callback when the TCP connection is established.
  
          Record references to the stream reader and the stream writer to avoid
          using private attributes ``_stream_reader`` and ``_stream_writer`` of
          :class:`~asyncio.StreamReaderProtocol`.