public void NullKeys()
{
var john = new TestPerson(null);
var people = new SynchronizedRangeObservableCollection <TestPerson>();
using (var query = people.ToActiveDictionary(p => new KeyValuePair <string, TestPerson>(p.Name, p)))
{
Assert.IsNull(query.OperationFault);
people.Add(john);
Assert.IsNotNull(query.OperationFault);
john.Name = "John";
Assert.IsNull(query.OperationFault);
john.Name = null;
Assert.IsNotNull(query.OperationFault);
people.Clear();
Assert.IsNull(query.OperationFault);
}
}