code: def associated_stream(self):
          
  
          if not self.important:
              raise InternalError("You may only call autocopied_stream on when DataStream.important is True", stream=self)
  
          if self.stream_id >= DataStream.ImportantSystemStorageStart:
              stream_type = DataStream.BufferedType
          else:
              stream_type = DataStream.OutputType
  
          return DataStream(stream_type, self.stream_id, True)
docs: Return the corresponding output or storage stream for an important system input.
  
          Certain system inputs are designed as important and automatically
          copied to output streams without requiring any manual interaction.
  
          This method returns the corresponding stream for an important system
          input.  It will raise an InternalError unlesss the self.important
          property is True.
  
          Returns:
              DataStream: The corresponding output or storage stream.
  
          Raises:
              InternalError: If this stream is not marked as an important system input.