Unsubscribe from event only if subscribed?

Unity Engine
1

Is there a quick way to check if an event actually has subscribed when unsubscribing, e.g not use a bool?

  private void OnDisable()
    {
       
        generator.SomeEvent-= SomeFunction;

    }
2

From inside the class the enent is defined in, you have access to the delegate invocation list.