code: def get_normalizer(
      normalizer: Union[TransformProtocolType, NormalizerLiterals]
  ) -> TransformProtocol:
      if isinstance(normalizer, str):
          try:
              return {
                  "PValNormalizer": PValNormalizer,
                  "ShiftAndScaleNormalizer": ShiftAndScaleNormalizer,
              }.get(normalizer)()
          except KeyError:
              raise NotImplementedError(
                  f"Normalizer {normalizer} not implemented."
              )
      return normalizer
  
file_path: alibi-detect/alibi_detect/od/base.py
imports: from alibi_detect.utils.missing_optional_dependency import import_optional
  from typing import Union
  from typing_extensions import Literal, Protocol, runtime_checkable
label_desc: Use image node_id 1 for calling a global function with example usage: get_normalizer(normalizer) and returns: normalizer, dict