will be created if it does not exist yet.
	 *
	 * @since 5.5.0
	 *
	 * @return WP_Block_Pattern_Categories_Registry The main instance.
	 */
	public static function get_instance() {
		if ( null === self::$instance ) {
			self::$instance = new self();
		}

		return self::$instance;
	}
}