public async Task GetClassifierTreeList_ReturnList()
        {
            // arrange
            var cancellationToken        = new CancellationToken();
            var unitOfWorkFactory        = new TransactionScopeUnitOfWorkFactory();
            var dbContextFactory         = new DefaultDbContextFactory();
            var classifierTreeRepository = new DbClassifierTreeRepository(dbContextFactory);
            var generator = new MasterDataDbGenerator(unitOfWorkFactory, dbContextFactory);
            var handler   = new GetClassifierTreeListHandler(classifierTreeRepository);

            using (var _ = unitOfWorkFactory.Create())
            {
                // default tree will be insered for HierarchyType.Groups
                await generator.InsertType(HierarchyType.Groups, cancellationToken);

                // act
                var result = await handler.Handle(new GetClassifierTreeList
                {
                    TypeCode = generator.TypeCode
                }, cancellationToken);

                // assert
                Assert.IsNotNull(result);
                Assert.AreEqual(1, result.TotalCount);
            }
        }