internal HtmlAttribute(HtmlToken token)
 {
     this.token = token;
 }
 internal AttributeValueTextReader(HtmlToken token)
 {
     this.token = token;
 }
 internal TagUnstructuredContentTextReader(HtmlToken token)
 {
     this.token = token;
 }
 internal TagNameTextReader(HtmlToken token)
 {
     this.token = token;
 }
 internal AttributeEnumerator(HtmlToken token)
 {
     this.token = token;
 }