public GrammarHintList GetHints(HintType hintType)
        {
            var result = new GrammarHintList();

            foreach (var item in this)
            {
                if (item.Core.HasHints())
                {
                    foreach (var hint in item.Core.Hints)
                    {
                        if (hint.HintType == hintType)
                        {
                            result.Add(hint);
                        }
                    }
                }
            }
            return(result);
        }