public static void ElementAtOrDefault(Labeled <ParallelQuery <int> > labeled, int count, int position)
        {
            // For unordered collections, which element is chosen isn't actually guaranteed, but an effect of the implementation.
            // If this test starts failing it should be split, and possibly mentioned in release notes.
            ParallelQuery <int> query = labeled.Item;

            Assert.Equal(position, query.ElementAtOrDefault(position));
        }
        public static void ElementAtOrDefault_OutOfRange(Labeled <ParallelQuery <int> > labeled, int count, int position)
        {
            ParallelQuery <int> query = labeled.Item;

            Assert.Equal(default(int), query.ElementAtOrDefault(position));
        }