static ExpressionBuilderFactoty()
        {
            var handlerTypes = TypeLoader.GetSubTypes(typeof(BaseExpressionBuilder));

            foreach (var type in handlerTypes)
            {
                BaseExpressionBuilder variableHandler = (BaseExpressionBuilder)Activator.CreateInstance(type);
                handles.Add(variableHandler);
            }
        }
        static VariableHandleFactory()
        {
            var handlerTypes = TypeLoader.GetSubTypes(typeof(BaseVariableHandler));

            foreach (var type in handlerTypes)
            {
                BaseVariableHandler variableHandler = (BaseVariableHandler)Activator.CreateInstance(type);
                handles.Add(variableHandler);
            }
        }