docs: def _ProcessRegistryKeySource(self, source):
      """Glob for paths in the registry."""
      keys = source.base_source.attributes.get("keys", [])
      if not keys:
        return
  
      interpolated_paths = artifact_utils.InterpolateListKbAttributes(
          input_list=keys,
          knowledge_base=self.knowledge_base,
          ignore_errors=self.ignore_interpolation_errors)
  
      glob_expressions = map(rdf_paths.GlobExpression, interpolated_paths)
  
      patterns = []
      for pattern in glob_expressions:
        patterns.extend(pattern.Interpolate(knowledge_base=self.knowledge_base))
      patterns.sort(key=len, reverse=True)
  
      file_finder_action = rdf_file_finder.FileFinderAction.Stat()
      request = rdf_file_finder.FileFinderArgs(
          paths=patterns,
          action=file_finder_action,
          follow_links=True,
          pathtype=rdf_paths.PathSpec.PathType.REGISTRY)
      action = vfs_file_finder.RegistryKeyFromClient
  
      yield action, request