def METHOD_NAME(self, editor: Gio.AppInfo):
    app_id = editor.get_id()
    fname = app_id
    keyfile = GLib.KeyFile.new()
    data_dirs = [GLib.get_user_data_dir()] + GLib.get_system_data_dirs()
    for data_dir in data_dirs:
        for path, directories, files in os.walk(data_dir):
            if fname in files:
                filename = os.path.join(data_dir, path, fname)
                if keyfile.load_from_file(
                        filename, GLib.KeyFileFlags.NONE):
                    return keyfile
    return None