code: def inject_url_defaults(self, endpoint: str, values: dict) -> None:
          
          functions = self.url_value_preprocessors[None]
          if '.' in endpoint:
              blueprint = endpoint.rsplit('.', 1)[0]
              functions = chain(functions, self.url_value_preprocessors[blueprint])  # type: ignore
  
          for function in functions:
              function(endpoint, values)
docs: Injects default URL values into the passed values dict.
  
          This is used to assist when building urls, see
          :func:`~quart.helpers.url_for`.