class_docstr: Make sure that preprocessors work with the chat bot.
class_docstr_tok: ["Make","sure","that","preprocessors","work","with","the","chat","bot","."]
code: def test_clean_whitespace(self):
      self.chatbot.preprocessors = [preprocessors.clean_whitespace]
      response = self.chatbot.get_response("Hello,    how are you?")
  
      self.assertEqual(response.text, "Hello, how are you?")
  
file_path: ChatterBot/tests/test_preprocessors.py
imports: from tests.base_case import ChatBotTestCase
  from chatterbot.conversation import Statement
  from chatterbot import preprocessors
label_desc: Use image node_id 1 for calling the PreprocessorIntegrationTestCase obj's underlying member method code with example usage: obj.test_clean_whitespace() without return types