def METHOD_NAME(evaluator: Evaluator,
                     extractors: List[extractor.Extractor]):
  """Verifies evaluator is matched with an extractor.
  Args:
    evaluator: Evaluator to verify.
    extractors: Extractors to use in verification.
  Raises:
    ValueError: If an Extractor cannot be found for the Evaluator.
  """
  if (evaluator.run_after and
      evaluator.run_after != extractor.LAST_EXTRACTOR_STAGE_NAME and
      not any(evaluator.run_after == x.stage_name for x in extractors)):
    raise ValueError(
        'Extractor matching run_after=%s for Evaluator %s not found' %
        (evaluator.run_after, evaluator.stage_name))