code: def test_learn_response(self):
      previous_response = Statement(text="Define Hemoglobin.")
      statement = Statement(
          text="Hemoglobin is an oxygen-transport metalloprotein."
      )
      self.chatbot.learn_response(statement, previous_response)
      results = list(self.chatbot.storage.filter(text=statement.text))
  
      self.assertIsLength(results, 1)
  
imports: from tests.base_case import ChatBotTestCase
  from chatterbot.logic import LogicAdapter
  from chatterbot.conversation import Statement
label_desc: Use image node_id 23 for calling the ChatterBotResponseTestCase obj's underlying member method code with example usage: obj.test_learn_response() without return types