public function validateApplicationTransactions(PhabricatorApplicationTransactionEditor $editor, $type, array $xactions)
 {
     $this->setFieldError(null);
     $errors = parent::validateApplicationTransactions($editor, $type, $xactions);
     if ($this->getRequired()) {
         $value = $this->getOldValueForApplicationTransactions();
         $transaction = null;
         foreach ($xactions as $xaction) {
             $value = $xaction->getNewValue();
             if (!$this->isValueEmpty($value)) {
                 $transaction = $xaction;
                 break;
             }
         }
         if ($this->isValueEmpty($value)) {
             $error = new PhabricatorApplicationTransactionValidationError($type, pht('Required'), pht('%s is required.', $this->getFieldName()), $transaction);
             $error->setIsMissingFieldError(true);
             $errors[] = $error;
             $this->setFieldError(pht('Required'));
         }
     }
     return $errors;
 }