code: public int doEndTag()
              throws JspException {
          if(hasErrors())
              reportErrors();
          else if(_valid) {
              closeTableTag(_appender);
              write(_sb.toString());
          }
  
          return EVAL_PAGE;
      }
docs: Complete rendering the tag.  If no errors have occurred, the content that
  the tag buffered is rendered.
  
  @return EVAL_PAGE to continue evaluating the page
  @throws JspException if an error occurs that can not be reported on the page