code: def shell_context_processor(self, func: Callable) -> Callable:
          
          self.shell_context_processors.append(func)
          return func
docs: Add a shell context processor.
  
          This is designed to be used as a decorator. An example usage,
  
          .. code-block:: python
  
              @app.shell_context_processor
              def additional_context():
                  return context