public function addLabel($label, $before = false, $icon = NULL)
 {
     $labelO = $label;
     if (\is_object($label) === false) {
         $labelO = new HtmlLabel("label-" . $this->identifier, $label);
         if (isset($icon)) {
             $labelO->addIcon($icon);
         }
     } else {
         $labelO->addToPropertyCtrl("class", "label", array("label"));
     }
     $this->addContent($labelO, $before);
     return $labelO;
 }