public void AddRange_EventMustBeFired()
        {
            var coll = new SilentObservableCollection <int>();
            NotifyCollectionChangedEventArgs arg = null;

            coll.CollectionChanged += (_, e) => arg = e;
            coll.AddRange(1, 2, 3, 45);
            Assert.IsNotNull(arg);
        }
        public void AddRange_AllValueMustAdded()
        {
            var set = new HashSet <int>
            {
                1, 2, 3, 4, 5, 67, 8, 91, 9, 87, 6, 5342, 2, 56, 43, 47
            };
            var coll = new SilentObservableCollection <int>();

            coll.AddRange(set);
            Assert.AreEqual(set.Count, coll.Count);
            var inSetCount = coll.Distinct().Where(x => set.Contains(x)).Count();

            Assert.AreEqual(set.Count, inSetCount);
        }