code: public static HtmlTree HEADING(HtmlTag headingTag, boolean printTitle,
              HtmlStyle styleClass, Content body) {
          HtmlTree htmltree = new HtmlTree(headingTag, nullCheck(body));
          if (printTitle)
              htmltree.setTitle(body);
          if (styleClass != null)
              htmltree.addStyle(styleClass);
          return htmltree;
      }
docs: Generates a heading tag (h1 to h6) with the title and style class attributes. It also encloses
  a content.
  
  @param headingTag the heading tag to be generated
  @param printTitle true if title for the tag needs to be printed else false
  @param styleClass stylesheet class for the tag
  @param body content for the tag
  @return an HtmlTree object for the tag