public TransitionInstance(Transition t)
 {
     transition = t;
 }
        private XElement writeTransition(Transition transition)
        {
            if (transition == null) { return null; }

            XElement transitionElement = new XElement(
                xN + TRANSITION,
                new XAttribute(ID, transition.Id),
                new XAttribute(FROM, transition.FromNode.Id),
                new XAttribute(TO, transition.ToNode.Id),
                new XAttribute(NAME, transition.Name),
                new XAttribute(DISPLAY_NAME, transition.DisplayName),
                new XElement(xN + CONDITION, transition.Condition),
                writeExtendedAttributes(transition.ExtendedAttributes)
                );
            return transitionElement;
        }