code: public static HtmlTree HEADING(HtmlTag headingTag, boolean printTitle, Content body) {
          return HEADING(headingTag, printTitle, null, body);
      }
docs: Generates a heading tag (h1 to h6) with the title attribute. It also encloses
  a content.
  
  @param headingTag the heading tag to be generated
  @param printTitle true if the title for the tag needs to be printed else false
  @param body content for the tag
  @return an HtmlTree object for the tag