public void CorrectlyHandlesNullValues()
{
var testModel = new TestModel();
testModel.IncludedCatelProperty = null;
var editableObject = testModel as IEditableObject;
editableObject.BeginEdit();
testModel.IncludedCatelProperty = "included";
editableObject.CancelEdit();
Assert.IsNull(testModel.IncludedCatelProperty);
}