public function deleteGroup($groupId)
{
$objectStates = $this->loadObjectStates($groupId);
foreach ($objectStates as $objectState) {
$this->objectStateGateway->deleteObjectStateLinks($objectState->id);
$this->objectStateGateway->deleteObjectState($objectState->id);
}
$this->objectStateGateway->deleteObjectStateGroup($groupId);
}