public void Validate(ILearner objectToValidate)
        {
            var uln = objectToValidate.ULNNullable;

            if (ConditionMet(uln, _ulnReferenceDataService.Exists(uln)))
            {
                HandleValidationError(RuleNameConstants.ULN_05, objectToValidate.LearnRefNumber);
            }
        }