class List: def append_front(self): un" Moves the front node to the rear of the List. Use: source.append_front() Returns: None \# Your code here return def prepend_rear(self): un Moves the rear node to the front of the List. Use: source.prepend_rear() Returns: None \# Your code here return def detect_loop(self): "II! Determines if the List contains a circular reference/loop. Use: circular = source. detect_loop() Returns: circular - True if source contains a circular reference, False otherwise (bool) circular = False \# Your code here