As you may know by now, we are integrating the design patterns we've studied into a practical project: building a smart home system. Throughout this final unit, you'll learn how to create and adapt various smart home devices using the Singleton, Builder, Composite, and Abstract Factory patterns. By the end, you will have a solid understanding of how these design patterns can make your smart home system more efficient, modular, and easier to maintain.

1. Singleton Pattern:

   • Purpose: Ensures a class has only one instance and provides a global point of access to it.
   • Steps:
     • Define a class (Singleton) with a static method to hold the single instance.
     • Implement the getInstance method to manage instance creation and access.

2. Builder Pattern:

   • Purpose: Constructs complex objects step by step, providing a flexible solution for object creation.
   • Steps:
     • Define a class (SmartHomeDevice) for the object.
     • Create a builder class (SmartHomeDeviceBuilder) with methods to set object properties and a method to return the final object.

3. Composite Pattern: