private void Begin(DependencyObject targetObject, INameScope nameScope, Int64 layer) { if (Storyboard == null) { throw new InvalidOperationException(SR.Get(SRID.Storyboard_StoryboardReferenceRequired)); } if (Name != null) { Storyboard.BeginCommon(targetObject, nameScope, _handoffBehavior, true /* == is controllable */, layer); } else { Storyboard.BeginCommon(targetObject, nameScope, _handoffBehavior, false /* == not controllable */, layer); } }