docs: def ask_file(message='Select file for open.', default='', title='', save=False):
      """
      A dialog to get a file name.
      The "default" argument specifies a file path.
  
      save=False -> file for loading
      save=True -> file for saving
  
      Return the file path that the user entered, or None if he cancels the operation.
  
      :param message: message to be displayed.
      :param save: bool 0 -> load , 1 -> save
      :param title: window title
      :param default: default file path
      :rtype: None or string
      """
      return backend_api.opendialog("ask_file", dict(message=message, default=default, title=title, save=save))