private bool IsUnSafe(HtmlAttribute attribute)
        {
            if (_unsafe.Contains(attribute.Name))
                return true;

            if (!string.IsNullOrEmpty(attribute.Value))
            {
                string val = attribute.Value.TrimStart(new char[] { ' ' }).ToLowerInvariant();
                if (val.StartsWith("javascript"))
                    return true;
            }

            return false;
        }
        public HtmlImageInfo(HtmlElement element)
        {
            Element = element;

            _src = element.Attributes.FirstOrDefault(p => p.Name == "src");
        }
 public void Add(string name, string value)
 {
     var item = new HtmlAttribute { Name = name.ToLower(), Value = value };
     this._attributes[name.ToLower()] = item;
 }