add ability to specify class using a string

models/engine/file_storage.py

@@ -29,7 +29,7 @@ def all(self, cls=None):
         if cls is not None:
             new_dict = {}
             for key, value in self.__objects.items():
-                if cls == value.__class__:
+                if cls == value.__class__ or cls == value.__class__.__name__:
                     new_dict[key] = value
             return new_dict
         return self.__objects