def testCheckedOutTo(self): """ A book should always be checked out to a customer or be back at the library(None) """ lib = Library() lib.add_books(self._book) self.assertIsNone(lib.books_all[0].checked_out_to) # when a book is checked out it should obtain status checked_out_to # to point to a cus cus = "Garry" lib.checkout(self._book,cus) self.assertEqual(cus,self._book.checked_out_to)