def METHOD_NAME(extracts: beam.pvalue.PCollection,
                     slice_spec: List[slicer.SingleSliceSpec],
                     eval_config: Optional[config_pb2.EvalConfig] = None,
                     materialize: bool = True) -> beam.pvalue.PCollection:
  return extracts | 'ExtractSliceKeys' >> beam.ParDo(
      ExtractSliceKeysFn(eval_config, materialize), slice_spec=slice_spec
  )