public void FirstAndLastAreDuplicatesCustomComparer()
{
string[] source = { "Prakash", "Alpha", "DAN", "dan", "Prakash" };
string[] expected = { "Prakash", "Prakash", "DAN", "dan", "Alpha" };
Assert.Equal(expected, source.AsQueryable().OrderByDescending(e => e, StringComparer.OrdinalIgnoreCase));
}