docs: def GotAll(self, baseline, results):
      """Anomaly if baseline vs result counts differ, an empty list otherwise."""
      num_base = len(baseline)
      num_rslt = len(results)
      if num_rslt > num_base:
        raise ProcessingError("Filter generated more results than base data: "
                              "%s > %s" % (num_rslt, num_base))
      if num_rslt == num_base and num_base > 0:
        return self.Issue("Found all", results)
      return []