public void DeleteAllCombinations()
        {
            DependencyManager man = new DependencyManager(dep);
            CompoundEdit      ce  = (CompoundEdit)man.DeleteAllCombinations();

            ce.EndAllEdits();
            Assert.IsFalse(test1.Combinations.Contains(combi4));
            Assert.IsFalse(test2.Combinations.Contains(combi3));
            Assert.IsFalse(dep.Combinations.Contains(combi4));
            Assert.IsFalse(dep.Combinations.Contains(combi2));
            Assert.IsFalse(dep.Combinations.Contains(combi1));
            Assert.IsFalse(dep.Combinations.Contains(combi3));
            ce.Undo();
            Assert.IsTrue(test1.Combinations.Contains(combi4));
            Assert.IsTrue(test2.Combinations.Contains(combi3));
            Assert.IsTrue(dep.Combinations.Contains(combi4));
            Assert.IsTrue(dep.Combinations.Contains(combi2));
            Assert.IsTrue(dep.Combinations.Contains(combi1));
            Assert.IsTrue(dep.Combinations.Contains(combi3));
        }