public void SourceManipulation()
{
var numbers = new RangeObservableCollection <int>(System.Linq.Enumerable.Range(0, 10));
using (var query = numbers.ActiveElementAtOrDefault(9))
{
Assert.IsNull(query.OperationFault);
Assert.AreEqual(9, query.Value);
numbers.Remove(9);
Assert.IsNull(query.OperationFault);
Assert.AreEqual(0, query.Value);
numbers.Add(30);
Assert.IsNull(query.OperationFault);
Assert.AreEqual(30, query.Value);
numbers.Insert(9, 15);
Assert.IsNull(query.OperationFault);
Assert.AreEqual(15, query.Value);
}
}