docs: def _SeparateTypes(self, metadata_value_pairs):
      """Separate files, registry keys, grep matches."""
      registry_pairs = []
      file_pairs = []
      match_pairs = []
      for metadata, result in metadata_value_pairs:
        if (result.stat_entry.pathspec.pathtype ==
            rdf_paths.PathSpec.PathType.REGISTRY):
          registry_pairs.append((metadata, result.stat_entry))
        else:
          file_pairs.append((metadata, result))
  
        match_pairs.extend([(metadata, match) for match in result.matches])
  
      return registry_pairs, file_pairs, match_pairs