/**
  * update properties of record by id
  *
  * @param string $_id record id
  * @param array  $_data key/value pairs with fields to update
  * @param Tinebase_Controller_Record_Interface $_controller
  * @return Tinebase_Record_Abstract record
  */
 protected function _updateProperties($_id, $_data, Tinebase_Controller_Record_Interface $_controller)
 {
     $record = $_controller->get($_id);
     // merge with new properties
     foreach ($_data as $field => $value) {
         $record->{$field} = $value;
     }
     $savedRecord = $_controller->update($record);
     return $this->_recordToJson($savedRecord);
 }