public function addObject(IcingaObject $object)
 {
     $this->content .= $object->toConfigString();
     $this->checksum = null;
     if ($object->hasProperty('object_type')) {
         $type = $object->object_type;
         switch ($type) {
             case 'object':
                 $this->cntObject++;
                 break;
             case 'template':
                 $this->cntTemplate++;
                 break;
         }
     }
     return $this;
 }