code: def add_app_template_filter(self, func: Callable, name: Optional[str]=None) -> None:
          
          self.record_once(lambda state: state.register_template_filter(func, name))
docs: Add an application wide template filter.
  
          This is designed to be used on the blueprint directly, and
          has the same arguments as
          :meth:`~quart.Quart.add_template_filter`. An example usage,
  
          .. code-block:: python
  
              def filter():
                  ...
  
              blueprint = Blueprint(__name__)
              blueprint.add_app_template_filter(filter)