by MJ Decorator is a design pattern used to dynamically ”decorate” (e.g. add new actions) another classes. Let’s say that you have class which describes Window. It can be opened or closed. Then, you decide to decorate it with curtains or to clean it – you  will do it yourself or hire somebody, who will be a decorator. Let’s create a simple project: 1) First of all, you need to add “Decorator” folder. Inside of this folder please create Window.cs class which will describe our window in the real world...