code: def prepare_metadata_for_build_wheel(metadata_directory, config_settings):
      
      backend = _build_backend()
      try:
          hook = backend.prepare_metadata_for_build_wheel
      except AttributeError:
          return _get_wheel_metadata_from_wheel(backend, metadata_directory,
                                                config_settings)
      else:
          return hook(metadata_directory, config_settings)
docs: Invoke optional prepare_metadata_for_build_wheel
  
      Implements a fallback by building a wheel if the hook isn't defined.