function add_ajax_action(
            $tag,
            $function_to_add,
            $priority = WP_FS__DEFAULT_PRIORITY
        ) {
            $this->_logger->entrance( $tag );

            return self::add_ajax_action_static(
                $tag,
                $function_to_add,
                $priority,
                $this->_module_id
            );
        }