public void HandleError()
        {
            var learnerValidationErrorHandler = new LearnerValidationErrorHandler();

            learnerValidationErrorHandler.Handle(new MessageLearner()
            {
                LearnRefNumber = "Test"
            }, "TestErrorName");

            learnerValidationErrorHandler.ErrorBag.Should().HaveCount(1);
        }
        public void HandleErrorParallel()
        {
            var learnerValidationErrorHandler = new LearnerValidationErrorHandler();

            Parallel.For(0, 1000, (i) =>
            {
                learnerValidationErrorHandler.Handle(new MessageLearner()
                {
                    LearnRefNumber = i.ToString()
                }, "TestErrorName");
            });

            for (int i = 0; i < 1000; i++)
            {
                learnerValidationErrorHandler.ErrorBag.Should().ContainSingle(eb => eb.LearnerReferenceNumber == i.ToString());
            }
        }