public void TestIsProperSubsetOf() { var a = new RedBlackSetTester<int>(); Assert.That(() => a.IsProperSubsetOf(null), Throws.InstanceOf<ArgumentNullException>()); Assert.That(a.IsProperSubsetOf(Enumerable.Range(1, 1))); Assert.That(a.IsProperSubsetOf(Enumerable.Empty<int>()), Is.False); a.AddRange(_primes); Assert.That(a.IsProperSubsetOf(_numbers)); a.AddRange(_even.Where(UpTo100)); Assert.That(a.IsProperSubsetOf(_numbers)); a.AddRange(_odd.Where(UpTo100)); Assert.That(a.IsProperSubsetOf(_numbers), Is.False); }