public ITagger <T> CreateTagger <T>(ITextView textView, ITextBuffer buffer) where T : ITag
        {
            QmlClassificationType.InitClassificationTypes(classificationTypeRegistry);
            if (!QmlClassificationType.ClassificationTypes.ContainsKey(ClassificationType))
            {
                QmlClassificationType.ClassificationTypes.Add(ClassificationType,
                                                              classificationTypeRegistry.GetClassificationType(ClassificationType));
            }

            return(QmlExpressionEval.Create(textView, buffer) as ITagger <T>);
        }
        public static QmlExpressionEval Create(ITextView textView, ITextBuffer buffer)
        {
            var _this = new QmlExpressionEval(textView, buffer);

            return(_this.Initialize(textView, buffer) ? _this : null);
        }