cleanup tf unittests: part 2 (#6260)

* cleanup torch unittests: part 2

* remove trailing comma added by isort, and which breaks flake

* one more comma

* revert odd balls

* part 3: odd cases

* more ["key"] -> .key refactoring

* .numpy() is not needed

* more unncessary .numpy() removed

* more simplification

tests/test_modeling_gpt2.py

@@ -152,7 +152,7 @@ class GPT2ModelTester:
         result = model(input_ids)
 
         self.parent.assertEqual(result.last_hidden_state.shape, (self.batch_size, self.seq_length, self.hidden_size))
-        self.parent.assertEqual(len(result["past_key_values"]), config.n_layer)
+        self.parent.assertEqual(len(result.past_key_values), config.n_layer)
 
     def create_and_check_gpt2_model_past(self, config, input_ids, input_mask, head_mask, token_type_ids, *args):
         model = GPT2Model(config=config)