docs: def _on_import_config(self, *args):
          """Callback method the the import button was clicked
  
          Shows a dialog allowing to import an existing configuration file
          """
          def handle_import(dialog_text, path_name):
              chooser = Gtk.FileChooserDialog(dialog_text, None,
                                              Gtk.FileChooserAction.SAVE,
                                              (Gtk.STOCK_CANCEL, Gtk.ResponseType.CANCEL,
                                               Gtk.STOCK_OPEN, Gtk.ResponseType.ACCEPT))
              chooser.set_current_folder(path_name)
              response = chooser.run()
              if response == Gtk.ResponseType.ACCEPT:
                  # get_filename() returns the whole file path inclusively the filename
                  config_file = chooser.get_filename()
                  config_path = dirname(config_file)
                  self._last_path = config_path
                  config_dict = yaml_configuration.config.load_dict_from_yaml(config_file)
                  config_type = config_dict.get("TYPE")
                  if config_type == "SM_CONFIG":
                      del config_dict["TYPE"]
                      self.core_config_model.update_config(config_dict, config_file)
                      logger.info("Imported Core Config from {0}".format(config_file))
                  elif config_type == "GUI_CONFIG":
                      del config_dict["TYPE"]
                      self.gui_config_model.update_config(config_dict, config_file)
                      logger.info("Imported GUI Config from {0}".format(config_file))
                  else:
                      logger.error("{0} is not a valid config file".format(config_file))
              elif response == Gtk.ResponseType.CANCEL:
                  logger.info("Import of configuration cancelled")
              chooser.destroy()
  
          handle_import("Import Config Config from", self._last_path)
  
          self.check_for_preliminary_config()
          self.update_path_labels()