code: protected Html unmarshal(StringBuilder sb) throws JAXBException {
          Html html = null;
          sb = replaceIframeEndTag(sb);
          sb = removeDoctypeDeclaration(sb);
          sb = replaceNamedEntity(sb);
          StringReader stringReader = new StringReader(sb.toString());
          html = (Html) jaxbContext.createUnmarshaller().unmarshal(stringReader);
          return html;
      }
docs: <p>
  unmarshal from html string to html object.
  </p>
  
  @param sb
  @return
  @throws JAXBException