public void RunOnce()
{
var source = new[]{
new { name="Prakash", custID=98088 },
new { name="Bob", custID=29099 },
new { name="Chris", custID=39033 },
new { name=(string)null, custID=30349 },
new { name="Prakash", custID=39030 }
};
string[] expected = { "Prakash", "Bob", "Chris", null, "Prakash" };
Assert.Equal(expected, source.RunOnce().Select(e => e.name));
Assert.Equal(expected, source.ToArray().RunOnce().Select(e => e.name));
Assert.Equal(expected, source.ToList().RunOnce().Select(e => e.name));
}