public static function instance()
 {
     if (!self::$instance) {
         self::$instance = new self();
     }
     return self::$instance;
 }
<?php

/**
 * Boostrap code for typography module
 *
 * @package Omega
 * @subpackage Typography
 *
 * @copyright (c) 2014 Oxygenna.com
 * @license **LICENSE**
 * @version 1.7.3
 * @author Oxygenna.com
 */
define('OXY_TYPOGRAPHY_DIR', OXY_THEME_DIR . 'vendor/oxygenna/oxygenna-typography/');
define('OXY_TYPOGRAPHY_URI', OXY_THEME_URI . 'vendor/oxygenna/oxygenna-typography/');
if (!class_exists('OxygennaTypography')) {
    require_once OXY_TYPOGRAPHY_DIR . 'inc/OxygennaTypography.php';
    global $oxy_typography;
    $oxy_typography = OxygennaTypography::instance();
}