code: def get_requires_for_build_sdist(config_settings):
      
      backend = _build_backend()
      try:
          hook = backend.get_requires_for_build_sdist
      except AttributeError:
          return []
      else:
          return hook(config_settings)
docs: Invoke the optional get_requires_for_build_wheel hook
  
      Returns [] if the hook is not defined.