docs: def GetReportDescriptor(cls):
      """Returns plugins' metadata in ApiReportDescriptor."""
      if cls.TYPE is None:
        raise ValueError("%s.TYPE is unintialized." % cls)
  
      if cls.TITLE is None:
        raise ValueError("%s.TITLE is unintialized." % cls)
  
      if cls.SUMMARY is None:
        raise ValueError("%s.SUMMARY is unintialized." % cls)
  
      return rdf_report_plugins.ApiReportDescriptor(
          type=cls.TYPE,
          name=cls.__name__,
          title=cls.TITLE,
          summary=cls.SUMMARY,
          requires_time_range=cls.REQUIRES_TIME_RANGE)