code: def get_results(self, stream, time_interval):
          
          return [StreamInstance(t, self.data[stream.stream_id][t])
                  for t in sorted(self.data[stream.stream_id]) if t in time_interval]
docs: Calculates/receives the documents in the stream interval determined by the stream
          :param stream: The stream reference
          :param time_interval: The time interval
          :return: The sorted data items