public static function _ajax_menu_icons_update_settings() {
		check_ajax_referer( self::UPDATE_KEY, self::UPDATE_KEY );

		if ( empty( $_POST['menu-icons']['settings'] ) ) {
			wp_send_json_error();
		}

		$redirect_url = self::_update_settings( $_POST['menu-icons']['settings'] ); // Input var okay.
		wp_send_json_success( array( 'redirectUrl' => $redirect_url ) );
	}