public function bootstrapClass($widthBT)
 {
     if (!is_array($widthBT)) {
         $obj = new OObject("obj");
         $obj->setWidthBT($widthBT);
         $widthBT = $obj->getWidthBT();
     }
     $class = "";
     foreach ($widthBT as $key => $value) {
         if (substr($key, 0, 1) == "w" && $value > 0) {
             $class .= " col-" . substr($key, 1) . "-" . $value . " ";
         }
         if (substr($key, 0, 1) == "o" && $value > 0) {
             $class .= " col-" . substr($key, 1) . "-offset-" . $value . " ";
         }
     }
     return $class;
 }