public void SourceManipulation()
{
var numbers = new SynchronizedRangeObservableCollection <int>(System.Linq.Enumerable.Range(1, 10));
using var query = numbers.ActiveCast <object>();
Assert.AreEqual(0, query.GetElementFaults().Count);
Assert.AreEqual(55, query.Cast <int>().Sum());
Assert.IsInstanceOfType(query[0], typeof(object));
numbers[0] += 10;
Assert.AreEqual(0, query.GetElementFaults().Count);
Assert.AreEqual(65, query.Cast <int>().Sum());
}