protected function add_sections( $sections, $tab ) {
            foreach ( $sections as $section_slug => $section_args ) {
                $section = $tab->add( new Section( $section_slug, $section_args ) );
                if ( is_wp_error( $section ) ) {
                    self::doing_it_wrong( __METHOD__, $section->get_error_message(), '0.5.0' );