code: def register(self, event_name):
          
          def registrar(func):
              self.callbacks[event_name].append(func)
  
              return func
  
          return registrar
docs: Decorator,
  
          Registers the decorated function as a callback for the `event_name`
          given.
  
          :param event_name: The name of the event to register for.
  
          Example:
              >>> callbacks = Callbacks()
              >>> @callbacks.register("my_event")
              ... def hello():
              ...     print("Hello world")
              ...
              >>> # Which then can be called
              >>> callbacks.call("my_event")
              Hello world