code: def _query_for_individual_audio(self, run, tag, sample, index):
      
      query_string = urllib.parse.urlencode({
          'run': run,
          'tag': tag,
          'sample': sample,
          'index': index,
      })
      return query_string
docs: Builds a URL for accessing the specified audio.
  
      This should be kept in sync with _serve_audio_metadata. Note that the URL is
      *not* guaranteed to always return the same audio, since audio may be
      unloaded from the reservoir as new audio entries come in.
  
      Args:
        run: The name of the run.
        tag: The tag.
        index: The index of the audio entry. Negative values are OK.
  
      Returns:
        A string representation of a URL that will load the index-th sampled audio
        in the given run with the given tag.