storage_get_count

[Sarerrdy]

I implemented the get Method in both FileStorage and DBStorage classes which retrieve an object based on its class and ID and returns the object if found, otherwise returns None.

I also implemented the count method in both FileStorage and DBStorage classes which returns the number of objects in storage. It can also return the number of objects of a specific class if provided.

I added 2 new methods to test both the get and count functions in both the test_db_storage.py and test_file_storage.py test files