public function __set($propertyName, $value)
 {
     switch ($propertyName) {
         case 'theme':
             $this->theme = $value;
             if ($this->_isConstructed) {
                 $this->engine->template_dir = realpath($this->themeRootPath) . '/' . $this->theme . '/';
                 $this->_addTraceInfo(__FILE__, __METHOD__, __LINE__, 'Template Directory Now Set To ' . $this->engine->template_dir);
             }
             break;
         default:
             parent::__set($propertyName, $value);
     }
 }