public void TestIndexOfInViews()
        {
            var initial        = Enumerable.Range(0, 100).Select(x => new KeyValuePair <int, string>(x, x.ToString())).ToList();
            var other          = Enumerable.Range(100, 100).Select(x => new KeyValuePair <int, string>(x, x.ToString())).ToList();
            var testCollection = new ConcurrentObservableDictionary <int, string>();

            testCollection.AddRange(initial);
            var collectionView = testCollection.CollectionView;
            var keysView       = testCollection.Keys;
            var valuesView     = testCollection.Values;

            // Test the IList implementation because it had a bug

            IList collectionList = (IList)testCollection.CollectionView;
            IList keysList       = (IList)testCollection.Keys;
            IList valuesList     = (IList)testCollection.Values;

            foreach (var item in initial)
            {
                Assert.IsTrue(testCollection.Contains(item));

                Assert.IsTrue(collectionView.Contains(item));
                Assert.IsTrue(keysView.Contains(item.Key));
                Assert.IsTrue(valuesView.Contains(item.Value));

                Assert.IsTrue(collectionList.Contains(item));
                Assert.IsTrue(keysList.Contains(item.Key));
                Assert.IsTrue(valuesList.Contains(item.Value));
            }

            foreach (var item in other)
            {
                Assert.IsFalse(testCollection.Contains(item));

                Assert.IsFalse(collectionView.Contains(item));
                Assert.IsFalse(keysView.Contains(item.Key));
                Assert.IsFalse(valuesView.Contains(item.Value));

                Assert.IsFalse(collectionList.Contains(item));
                Assert.IsFalse(keysList.Contains(item.Key));
                Assert.IsFalse(valuesList.Contains(item.Value));
            }

            for (int i = 0; i < initial.Count; ++i)
            {
                Assert.AreEqual(initial[i], collectionView[i]);
                Assert.AreEqual(initial[i].Key, keysView[i]);
                Assert.AreEqual(initial[i].Value, valuesView[i]);

                Assert.AreEqual(initial[i], collectionList[i]);
                Assert.AreEqual(initial[i].Key, keysList[i]);
                Assert.AreEqual(initial[i].Value, valuesList[i]);

                Assert.AreEqual(i, collectionView.IndexOf(initial[i]));
                Assert.AreEqual(i, keysView.IndexOf(initial[i].Key));
                Assert.AreEqual(i, valuesView.IndexOf(initial[i].Value));

                Assert.AreEqual(i, collectionList.IndexOf(initial[i]));
                Assert.AreEqual(i, keysList.IndexOf(initial[i].Key));
                Assert.AreEqual(i, valuesList.IndexOf(initial[i].Value));
            }
        }
        public void TestManyOperations()
        {
            // Create some random, but unique items
            // Use a fixed seed for consistency in results
            Random        random       = new Random(1);
            HashSet <int> baseItemsSet = new HashSet <int>();

            while (baseItemsSet.Count < 1_100_000)
            {
                baseItemsSet.Add(random.Next());
            }

            // Create 2 collections, 1 to test, and 1 to compare against
            var testCollection = new ConcurrentObservableDictionary <string, string>();
            var list           = new List <KeyValuePair <string, string> >();

            // Create 1,000,000 items to add and insert
            var itemsToAdd =
                baseItemsSet
                .Take(1_000_000)
                .Select(x => Swordfish.NET.Collections.KeyValuePair.Create($"Key {x}", $"Value {x}"))
                .ToList();

            // Create 100,000 items to insert
            var itemsToInsert =
                baseItemsSet
                .Skip(1_000_000)
                .Take(100_000)
                .Select(x => Swordfish.NET.Collections.KeyValuePair.Create($"Insert Key {x}", $"Insert Value {x}"))
                .ToList();

            // Create items to remove
            var itemsToRemove =
                itemsToInsert
                .Take(1000)
                .ToList();

            foreach (var item in itemsToAdd)
            {
                testCollection.Add(item.Key, item.Value);
                list.Add(item);
            }

            // Check items are equal count
            Assert.IsTrue(list.Count == testCollection.Count, "Added Items correct count");

            // Check items are equal order
            var allEqualAfterAdd =
                list
                .Zip(testCollection, (a, b) => (a.Key == b.Key) && (a.Value == b.Value))
                .All(a => a);

            Assert.IsTrue(allEqualAfterAdd, "Added items correct order");

            // Test inserting items

            int insertIndex = itemsToInsert.Count + 100;

            foreach (var item in itemsToInsert)
            {
                // We have the function but it's there for other reasons
                testCollection.Insert(insertIndex, item);

                list.Insert(insertIndex, item);

                insertIndex--;
            }

            // Check items are equal count
            Assert.IsTrue(list.Count == testCollection.Count, "Items correct count after inserting");

            // Check items are equal order
            var allEqualAfterInsert =
                list
                .Zip(testCollection, (a, b) => (a.Key == b.Key) && (a.Value == b.Value))
                .All(a => a);

            Assert.IsTrue(allEqualAfterAdd, "Items correct order after insert");

            // Test removing items

            foreach (var item in itemsToRemove)
            {
                testCollection.Remove(item.Key);
                list.Remove(item);
            }

            // Check items are equal count
            Assert.IsTrue(list.Count == testCollection.Count, "Items correct count after removing");

            // Check items are equal order
            var allEqualAfterRemove =
                list
                .Zip(testCollection, (a, b) => (a.Key == b.Key) && (a.Value == b.Value))
                .All(a => a);

            Assert.IsTrue(allEqualAfterRemove, "Items correct order after removing");

            // Test contains

            var containsAll = list
                              .All(kv => testCollection.Contains(kv));

            Assert.IsTrue(containsAll, "Contains all the items is true");

            var containsNone = itemsToRemove
                               .Any(kv => testCollection.ContainsKey(kv.Key));

            Assert.IsFalse(containsNone, "Contains any of the removed items is false");

            // Test removing at

            int removeAtIndex = list.Count - 30;

            while (removeAtIndex >= 0 && list.Count > 0)
            {
                list.RemoveAt(removeAtIndex);
                testCollection.RemoveAt(removeAtIndex);
                removeAtIndex -= 30;
            }

            // Check items are equal count
            Assert.IsTrue(list.Count == testCollection.Count, "Items correct count after removing at index");

            // Check items are equal order
            var allEqualAfterRemoveAt =
                list
                .Zip(testCollection, (a, b) => (a.Key == b.Key) && (a.Value == b.Value))
                .All(a => a);

            Assert.IsTrue(allEqualAfterRemoveAt, "Items correct order after removing at index");
        }