public void ComplexDistinct1()
{
var valueStack = new Stack <Tuple <int> >();
var errorStack = new Stack <Exception>();
bool isComplete = false;
var obs = new PushSubject <Tuple <int> >();
var output = obs.Distinct(l => l.Item1);
output.Subscribe(valueStack.Push, () => isComplete = true, errorStack.Push);
obs.PushValue(new Tuple <int>(1));
Assert.AreEqual(1, valueStack.Peek().Item1, "the input value should be issued");
obs.PushValue(new Tuple <int>(2));
Assert.AreEqual(2, valueStack.Peek().Item1, "the input value should be issued");
obs.PushValue(new Tuple <int>(1));
Assert.AreEqual(2, valueStack.Count, "the input value should not be issued as it has been submitted first");
obs.PushValue(new Tuple <int>(3));
Assert.AreEqual(3, valueStack.Peek().Item1, "the input value should be issued");
obs.PushValue(new Tuple <int>(1));
Assert.AreEqual(3, valueStack.Count, "the input value should not be issued as it has been submitted first");
obs.PushValue(new Tuple <int>(2));
Assert.AreEqual(3, valueStack.Count, "the input value should not be issued as it has been submitted first");
obs.Complete();
Assert.IsTrue(isComplete, "the stream should be completed");
}