Single Reactive Property

    public class DrawingFeature : Feature {
        private Drawing drawing_;
        public event EventHandler DrawingChanged;
        private NonBlockingMutex inDrawingChanged_;

        protected void OnDrawingChanged()
        {
            using (inDrawingChanged_.AcquireOrThrow()) {
                if (DrawingChanged != null) {
                    DrawingChanged(this, EventArgs.Empty);
                }

                OnFeatureChanged();
            }
        }
        public Drawing Drawing {
            get
            {
                return drawing_;
            }
            set
            {
                drawing_ = value;
                OnDrawingChanged();
            }
        }
    }