public static function instance()
 {
     if (is_null(self::$_instance)) {
         self::$_instance = new self();
     }
     return self::$_instance;
 }
 /**
  * Returns payment methods info html
  *  
  * @param  array $atts
  * @return string
  */
 public static function payment_methods_info($atts)
 {
     WC_GZD_Payment_Gateways::instance()->manipulate_gateways();
     ob_start();
     wc_get_template('global/payment-methods.php');
     $return = '<div class="woocommerce woocommerce-gzd">' . ob_get_clean() . '</div>';
     return $return;
 }