private static void ValidateResult <T>(T x, Node <T> list, params T[] expectedResult)
            where T : IEquatable <T>, IComparable <T>
        {
            var result = Question2_4.PartitionList(list, x);

            ListHelpers.ValidateLinkedListContent(result, expectedResult);
        }
 public void InvalidInputsTest()
 {
     // Null node
     TestHelpers.AssertExceptionThrown(() => { Question2_4.PartitionList(null, 3); }, typeof(ArgumentNullException));
 }