I'm reading "Head first design patterns" (here you can find exact example mentioned in book)
While going through Decorator design pattern, everything was crisp and clear until I stumbled into this
They are explaining decorator using
Extensions. I don't think extending a class through 'Extensions' results in decorator design pattern since we can't add properties to classes. As I understand, key to decorator is it ability to wraps other objects infinity, this is not possible here, although we can add functionality to existing class without inheriting it.
Delegation. Delegation here is completely out of context. Isn't delegation itself a design pattern?