public void ShouldUnlinkProjects()
        {
            var solution = new MockIVsSolution();
            TestableProjectLinkTracker tracker = new TestableProjectLinkTracker(new MockDocumentTracker(), solution);
            var sourceVsHierarchy = new MockVsHierarchy();
            var targetVsHierarchy = new MockVsHierarchy();
            solution.Hierarchies.Add(sourceVsHierarchy);
            solution.Hierarchies.Add(targetVsHierarchy);
            tracker.AddProjectLink(sourceVsHierarchy, targetVsHierarchy);
            targetVsHierarchy.GetPropertyProjectValue.Globals.set_VariablePersistsCalled = false;

            tracker.UnlinkProjects(sourceVsHierarchy.GetPropertyProjectIdGuidValue, targetVsHierarchy.GetPropertyProjectIdGuidValue);

            Assert.AreEqual(0, tracker.GetProjectLinks().Count());
            Assert.IsTrue(targetVsHierarchy.GetPropertyProjectValue.Globals.set_VariablePersistsCalled);
            Assert.IsFalse(targetVsHierarchy.GetPropertyProjectValue.Globals.set_VariablePersistsArgumentValue);
        }