code: public static HtmlTree FRAMESET(String cols, String rows, String title, String onload) {
          HtmlTree htmltree = new HtmlTree(HtmlTag.FRAMESET);
          if (cols != null)
              htmltree.addAttr(HtmlAttr.COLS, cols);
          if (rows != null)
              htmltree.addAttr(HtmlAttr.ROWS, rows);
          htmltree.addAttr(HtmlAttr.TITLE, nullCheck(title));
          htmltree.addAttr(HtmlAttr.ONLOAD, nullCheck(onload));
          return htmltree;
      }
docs: Generates a FRAMESET tag.
  
  @param cols the size of columns in the frameset
  @param rows the size of rows in the frameset
  @param title the title for the frameset
  @param onload the script to run when the document loads
  @return an HtmlTree object for the FRAMESET tag