docstr: Test that an additional data attribute can be added to the statement
  and that this attribute is saved.
code: def test_additional_attributes_saved(self):
      """
      Test that an additional data attribute can be added to the statement
      and that this attribute is saved.
      """
      self.chatbot.get_response("Hello", conversation="test")
      results = list(
          self.chatbot.storage.filter(
              text="Hello", in_response_to=None, conversation="test"
          )
      )
  
      self.assertEqual(len(results), 1)
      self.assertIn("pos_tags:NN", results[0].get_tags())
  
file_path: ChatterBot/tests/logic/test_data_cache.py
imports: from tests.base_case import ChatBotTestCase
  from chatterbot.logic import LogicAdapter
  from chatterbot.trainers import ListTrainer
label_desc: Use image node_id 2 for calling the DataCachingTests obj's underlying member method code with example usage: obj.test_additional_attributes_saved() without return types