public void TestUnion_EmptySet() { GenericSet <int> gs1 = new GenericSet <int>(); for (int i = 1; i <= 8; i++) { gs1.Add(i); } Console.WriteLine(gs1); GenericSet <int> gs2 = new GenericSet <int>(); Assert.That(gs2.IsEmpty, Is.True); Console.WriteLine(gs2); GenericSet <int> union = gs1.Union(gs2); Assert.That(union.Size, Is.EqualTo(gs1.Size)); Assert.That(union.Contains(15), Is.False); Assert.That(union.Contains(1), Is.True); }