code: def post_message(driver, message, msg_dur, style="info"):
      
      if not msg_dur:
          msg_dur = settings.DEFAULT_MESSAGE_DURATION
      msg_dur = float(msg_dur)
      message = re.escape(message)
      message = escape_quotes_if_needed(message)
      messenger_script = ('''Messenger().post({message: "%s", type: "%s", '''
                          '''hideAfter: %s, hideOnNavigate: true});'''
                          % (message, style, msg_dur))
      try:
          driver.execute_script(messenger_script)
      except Exception:
          activate_messenger(driver)
          set_messenger_theme(driver)
          try:
              driver.execute_script(messenger_script)
          except Exception:
              time.sleep(0.2)
              activate_messenger(driver)
              time.sleep(0.2)
              set_messenger_theme(driver)
              time.sleep(0.5)
              driver.execute_script(messenger_script)
docs: A helper method to post a message on the screen with Messenger.
          (Should only be called from post_message() in base_case.py)