Is not that clear with the decorator? I slightly changed the code for a better understanding.

Question

https://code.sololearn.com/cZZzYKGl9klL/?ref=app

Answer 1

Here is an example of what a decorator may be useful for:
https://code.sololearn.com/cD09ijlIS6Ev/?ref=app

Answer 2

Are you trying to use the decorator design pattern? The decorator must be like a component to the class. Look online for pseudo code and more explanation on the design pattern.