List with filter bench marks

    public class ListFilterPerf
    {

        private static readonly ICollection<int> Items = Enumerable.Range(1, 1_000_000).ToList();



        [Fact]
        public void ListOnly_Range()
        {
            using (var list = new SourceList<int>())
            {
                list.AddRange(Items);
            }

        }

        [Fact]
        public void ListOnly_Many()
        {
            using (var list = new SourceList<int>())
            {
                foreach (var item in Items)
                    list.Add(item);
            }
        }

        [Fact]
        public void Filter_RangeBeforeSubscribe()
        {
            using (var list = new SourceList<int>())
            {
                list.AddRange(Items);

                list.Connect().Filter(v => v % 2 == 0).Subscribe(v => { });
            }
        }

        [Fact]
        public void Filter_ItemsBeforeSubscribe()
        {
            using (var list = new SourceList<int>())
            {
                foreach (var item in Items)
                    list.Add(item);

                list.Connect().Filter(v => v % 2 == 0).Subscribe(v => { });
            }
        }

        [Fact]
        public void Filter_ItemsAfterSubscribe()
        {
            using (var list = new SourceList<int>())
            {
                list.Connect().Filter(v => v % 2 == 0).Subscribe(v => { });

                foreach (var item in Items)
                    list.Add(item);
            }

        }

        [Fact]
        public void Filter_RangeAfterSubscribe()
        {
            using (var list = new SourceList<int>())
            {
                list.Connect().Filter(v => v % 2 == 0).Subscribe(v => { });

                list.AddRange(Items);
            }
        }
   
        [Fact]
        public void BufferInitial()
        {
            var sheduler = new TestScheduler();
            using (var list = new SourceList<int>())
            {

                int count = 0;
                list.Connect()
                    .BufferInitial(TimeSpan.FromMilliseconds(250), sheduler)
                    .Filter(v => v % 2 == 0)
                    .Subscribe(v => { count = v.TotalChanges; });

                foreach (var item in Items)
                    list.Add(item);

                sheduler.AdvanceBy(TimeSpan.FromMilliseconds(251).Ticks);

                count.Should().Be(500_000);

                list.Add(2);
                count.Should().Be(1);
            }

        }

    }