public void IsProperSupersetOfTest()
 {
     Assert.IsTrue(testSet.IsProperSupersetOf(new int[] { 25, 1992, -72 }));
     Assert.IsFalse(testSet.IsProperSupersetOf(new int[] { 25, 1992, 128, 129 }));
     Assert.IsFalse(testSet.IsProperSupersetOf(new int[] { 15, 19, 25, 128, 1992, 54, -7, -72 }));
 }