How to use the tartube.downloads.VideoDownloader.ERROR function in tartube

# If the downloads.VideoDownloader object collected any
                #   youtube-dl error/warning messages, display them in the
                #   Error List
                if media_data_obj.error_list or media_data_obj.warning_list:
                    GObject.timeout_add(
                        0,
                        app_obj.main_win_obj.errors_list_add_row,
                        media_data_obj,
                    )

                # In the event of an error, nothing updates the video's row in
                #   the Video Catalogue, and therefore the error icon won't be
                #   visible
                # Do that now (but don't if mainwin.ComplexCatalogueItem
                #   objects aren't being used in the Video Catalogue)
                if return_code == VideoDownloader.ERROR \
                and isinstance(media_data_obj, media.Video) \
                and app_obj.catalogue_mode != 'simple_hide_parent' \
                and app_obj.catalogue_mode != 'simple_show_parent':
                    GObject.timeout_add(
                        0,
                        app_obj.main_win_obj.video_catalogue_update_row,
                        media_data_obj,
                    )

                # Call the destructor function of VideoDownloader object
                self.video_downloader_obj.close()

                # This worker is now available for a new job
                self.available_flag = True

                # Send a message to the Output Tab's summary page