public static Expression Parse(ConfigNode configNode)
        {
            Expression e = new Expression();

            e.Load(configNode);

            return(e);
        }
        public static Expression Parse(ConfigNode configNode, DataNode dataNode, ExpressionFactory factory)
        {
            Expression e = new Expression(dataNode);
            e.factory = factory;
            e.Load(configNode);
            e.factory = null;

            return e;
        }
        public static Expression Parse(ConfigNode configNode, DataNode dataNode, ExpressionFactory factory)
        {
            Expression e = new Expression(dataNode);

            e.factory = factory;
            e.Load(configNode);
            e.factory = null;

            return(e);
        }