init_hooks(); } return self::$instance; } /** * Initalize the hooks as needed. */ private function init_hooks() { /* * Load some scripts asynchronously. */ add_filter( 'script_loader_tag', array( $this, 'script_add_async' ), 10, 2 ); } /** * A public method for adding the async script. * * @param string $script_handle Script handle. */ public function add_async_script( $script_handle ) { $this->defer_script_handles[] = $script_handle; } /** * Add an async attribute to scripts that can be loaded deferred. * https://developer.mozilla.org/en-US/docs/Web/HTML/Element/script * * @param string $tag The