code: def _SetOptions(self, options, options_class_name):
      
      self._options = options
      self._options_class_name = options_class_name
  
      # Does this descriptor have non-default options?
      self.has_options = options is not None
docs: Sets the descriptor's options
  
      This function is used in generated proto2 files to update descriptor
      options. It must not be used outside proto2.