code: def distributions_impl(self, tag, run):
      
      (histograms, mime_type) = self._histograms_plugin.histograms_impl(
          tag, run, downsample_to=self.SAMPLE_SIZE)
      return ([self._compress(histogram) for histogram in histograms],
              mime_type)
docs: Result of the form `(body, mime_type)`, or `ValueError`.