', esc_html__( 'Premium', 'quadmenu' ) ), 'edit_posts', self::$panel_slug . '_premium', array( $this, 'add_panel' ) ); } function add_panel() { global $submenu; include QUADMENU_PLUGIN_DIR . '/lib/panel/pages/parts/header.php'; include QUADMENU_PLUGIN_DIR . '/lib/panel/pages/premium.php'; } public static function instance() { if ( ! isset( self::$instance ) ) { self::$instance = new self(); } return self::$instance; } }