/**
  *
  * @return array
  */
 public static function getAllAllowedCountries()
 {
     if (!is_array(self::$_allAllowedCountries)) {
         $allAllowedCountries = trim(Mage::getStoreConfig("payment/zitec_dpd_cashondelivery/all_allowed_countries"));
         if ($allAllowedCountries) {
             self::$_allAllowedCountries = explode(",", Mage::getStoreConfig("payment/zitec_dpd_cashondelivery/all_allowed_countries"));
         } else {
             self::$_allAllowedCountries = array();
         }
     }
     return self::$_allAllowedCountries;
 }