public static void SequenceEqual_SharedRight_Cancellation(Labeled <ParallelQuery <int> > left, Labeled <ParallelQuery <int> > right, int count)
{
IntegerRangeSet seen = new IntegerRangeSet(0, count);
CancellationTokenSource cs = new CancellationTokenSource();
Assert.Throws <OperationCanceledException>(() => left.Item.Except(ParallelEnumerable.Range(0, count).Select(x => { cs.Cancel(); seen.Add(x); return(x); }))
.SequenceEqual(right.Item.WithCancellation(cs.Token)));
// Canceled query means some elements should not be seen.
Assert.False(seen.All(x => x.Value));
}