public void TestNullDatasourceHandeler() { IDataSource dataSource = new DataSource.DataSource(null); IDecisionService service = new DecisionService(dataSource); Assert.Throws <NodeNotFoundException>(() => service.GetFirstQuestion()); Assert.Throws <NodeNotFoundException>(() => service.GetFirstNode()); Assert.Null(service.GetFullTree()); //Assert.(3, _service.GetTreeMaxpath()); }