docstr: Test that a matching response is returned
  when an exact match exists.
docstr_tok: ["Test","that","a","matching","response","is","returned","when","an","exact","match","exists","."]
code: def test_answer_to_known_input(self):
      """
      Test that a matching response is returned
      when an exact match exists.
      """
      input_text = "What... is your favourite colour?"
      response = self.chatbot.get_response(input_text)
  
      self.assertIn("Blue", response.text)
  
imports: from tests.base_case import ChatBotTestCase
  from chatterbot.trainers import ListTrainer
  from chatterbot import preprocessors
label_desc: Use image node_id 2 for calling the ChatterBotResponseTests obj's underlying member method code with example usage: obj.test_answer_to_known_input() without return types