def testParsersRetrieval(self):
    for processor in parsers.Parser.classes.values():
      if (not hasattr(processor, "output_types") or
          not isinstance(processor.output_types, (list, tuple))):
        raise parsers.ParserDefinitionError("Missing output_types on %s" %
                                            processor)

      for output_type in processor.output_types:
        if output_type not in rdfvalue.RDFValue.classes:
          raise parsers.ParserDefinitionError(
              "Parser %s has an output type that is an unknown type %s" %
              (processor, output_type))
Check the parsers are valid.
dataset/ETHPy150Open google/grr/grr/lib/artifact_utils_test.py/ArtifactParserTest.testParsersRetrieval