public void TestIsProperSupersetOf() { var a = new RedBlackSetTester<int>(); Assert.That(() => a.IsProperSupersetOf(null), Throws.InstanceOf<ArgumentNullException>()); Assert.That(a.IsProperSupersetOf(Enumerable.Empty<int>()), Is.False); Assert.That(a.IsProperSupersetOf(Enumerable.Range(1, 1)), Is.False); a.Add(2); Assert.That(a.IsProperSupersetOf(Enumerable.Empty<int>())); a.AddRange(_odd); Assert.That(a.IsProperSupersetOf(_primes)); }