This chapter is from the book
Nonvisual Decorators
Decorators, of course, are not limited to objects that enhance visual classes. You can add or modify the methods of any object in a similar fashion. In fact, nonvisual objects can be easier to decorate because there may be fewer methods to intercept and forward. Whenever you put an instance of a class inside another class and have the outer class operate on it, you are essentially “decorating” that inner class. This is one of the most common tools for programming available in Visual Studio.NET.