/**
  * this method checks, wheather all mandatory properties were set.
  * If done so, true is returned, otherwise false.
  * @return If done so, true is returned, otherwise false.
  */
 function checkMandatory()
 {
     if (parent::checkMandatory() && strlen($this->getTransactionId()) > 0) {
         return true;
     } else {
         return false;
     }
 }
 /**
  * this method checks, whether all mandatory properties were set.
  * If done so, true is returned, otherwise false.
  * @return If done so, true is returned, otherwise false.
  */
 function checkMandatory()
 {
     if (parent::checkMandatory() == true && strlen($this->getIssuerId()) > 0 && strlen($this->getMerchantReturnUrl()) > 0 && strlen($this->getPurchaseID()) > 0 && strlen($this->getAmount()) > 0 && strlen($this->getCurrency()) > 0 && strlen($this->getExpirationPeriod()) > 0 && strlen($this->getLanguage()) > 0 && strlen($this->getEntranceCode()) > 0 && strlen($this->getDescription()) > 0) {
         return true;
     } else {
         return false;
     }
 }