[Expression-Tree] - Get regex context menu

        // this method is written to fix Subtitle Edit's GetRegExContextMenu(Combobox/TextBox)

        // make more sense as an extension method.
        public static Action<TControl, string> BuildContextMenuRegex<TControl>()
        {
            var setMethod = typeof(TControl).GetProperty("SelectedText").GetSetMethod();
            var instanceParam = Expression.Parameter(typeof(TControl), "instance");
            var regexTokenParam = Expression.Parameter(typeof(string), "regexToken");
            var lambaExp = Expression.Lambda<Action<TControl, string>>(Expression.Call(instanceParam, setMethod, regexTokenParam), instanceParam, regexTokenParam);
            return lambaExp.Compile();
        }