## Facade Pattern

### Ex:

Design and implement a facade for a library management system. The system should allow users to borrow and return books, search for books by title or author, and check the availability of a particular book.

Your facade should simplify the interface for these operations and hide the complexity of the underlying subsystems $($e$.$g$.,$ the database or book inventory system$).$

Here are some specific requirements for the assignment:

$1.$ Define the interface for the facade, which should include methods for borrowing and returning books, searching for books, and checking book availability.

$2.$ Implement the facade using the facade design pattern. You should create separate subsystems for the book inventory system and the user management system.

$3.$ Write test cases to verify that the facade works correctly. Your tests should cover all the operations provided by the facade.

$4.$ Optionally, you can also add additional features to the library management system, such as the ability to reserve books or view the borrower history for a particular book.

$5.$ Finally, write a brief report on your implementation, explaining the design choices you made and how the facade pattern simplified the interface for the library management system.