@Override
 public int hashCode() {
   int result = _specification.hashCode();
   result = 31 * result + (_value != null ? _value.hashCode() : 0);
   result = 31 * result + (_result != null ? _result.hashCode() : 0);
   result = 31 * result + (_exceptionClass != null ? _exceptionClass.hashCode() : 0);
   result = 31 * result + (_exceptionMsg != null ? _exceptionMsg.hashCode() : 0);
   result = 31 * result + (_stackTrace != null ? _stackTrace.hashCode() : 0);
   result = 31 * result + (_missingInputs != null ? _missingInputs.hashCode() : 0);
   result = 31 * result + (_originalRequirements != null ? _originalRequirements.hashCode() : 0);
   return result;
 }