code: def load_url(self, url, force=False, reload_seconds=0,
                   callback_function=None):
          
          def launch_callback():
              """Loads requested URL after app launched."""
              should_reload = not force and reload_seconds not in (0, None)
              reload_milliseconds = (0 if not should_reload
                                     else reload_seconds * 1000)
              msg = {
                  "url": url,
                  "force": force,
                  "reload": should_reload,
                  "reload_time": reload_milliseconds
              }
  
              self.send_message(msg, inc_session_id=True,
                                callback_function=callback_function)
  
          self.launch(callback_function=launch_callback)
docs: Starts loading a URL with an optional reload time
          in seconds.
  
          Setting force to True may load pages which block
          iframe embedding, but will prevent reload from
          working and will cause calls to load_url()
          to reload the app.