public void GetElementByRevRank()
{
var list = new SortSet <int, int>();
for (var i = 0; i < 10; i++)
{
list.Add(i, i);
}
Assert.AreEqual(6, list.GetElementByRevRank(3));
Assert.AreEqual(9, list.GetElementByRevRank(0));
Assert.AreEqual(0, list.GetElementByRevRank(9));
}