protected function fillTransaction(SimpleXMLElement $xml)
 {
     $referencePopulator = new MerchantReferencePopulator(new MerchantReference('ChangePassword', uniqid()));
     $configurationPopulator = new VtidConfigurationTxnPopulator();
     $configurationPopulator->setPassword($this->password);
     $referencePopulator->createElement($xml->addChild('TxnDetails'));
     $configurationPopulator->createElement($xml->addChild('VtidConfigurationTxn'));
 }
 /**
  * @param MerchantReference $reference
  * @return TxnFullDetailsPopulator
  */
 public function setReference(MerchantReference $reference)
 {
     $this->referencePopulator->setReference($reference);
     return $this;
 }