docs: def parse_histogram(metric, histogram):
      """Iterates over histogram data, yielding metric-value pairs."""
      for match in HISTOGRAM.finditer(histogram):
          percentile, value = match.groups()
          value = float(value)
  
          if not isnan(value):
              try:
                  yield metric + PERCENTILE_SUFFIX[percentile], value
  
              # In case Envoy adds more
              except KeyError:
                  yield '{}.{}percentile'.format(metric, percentile[1:].replace('.', '_')), value