public void RemoveTest()
        {
            ImmutableSegmentedList <int> list = ImmutableSegmentedList <int> .Empty;

            for (int i = 1; i <= 10; i++)
            {
                list = list.Add(i * 10);
            }

            list = list.Remove(30);
            Assert.Equal(9, list.Count);
            Assert.False(list.Contains(30));

            list = list.Remove(100);
            Assert.Equal(8, list.Count);
            Assert.False(list.Contains(100));

            list = list.Remove(10);
            Assert.Equal(7, list.Count);
            Assert.False(list.Contains(10));

            var removeList = new int[] { 20, 70 };

            list = list.RemoveAll(removeList.Contains);
            Assert.Equal(5, list.Count);
            Assert.False(list.Contains(20));
            Assert.False(list.Contains(70));

            System.Collections.Immutable.IImmutableList <int> list2 = ImmutableSegmentedList <int> .Empty;
            for (int i = 1; i <= 10; i++)
            {
                list2 = list2.Add(i * 10);
            }

            list2 = System.Collections.Immutable.ImmutableList.Remove(list2, 30);
            Assert.Equal(9, list2.Count);
            Assert.False(list2.Contains(30));

            list2 = System.Collections.Immutable.ImmutableList.Remove(list2, 100);
            Assert.Equal(8, list2.Count);
            Assert.False(list2.Contains(100));

            list2 = System.Collections.Immutable.ImmutableList.Remove(list2, 10);
            Assert.Equal(7, list2.Count);
            Assert.False(list2.Contains(10));

            list2 = list2.RemoveAll(removeList.Contains);
            Assert.Equal(5, list2.Count);
            Assert.False(list2.Contains(20));
            Assert.False(list2.Contains(70));
        }