public function gc($lifeTime) {
        // search the entities that need to be deleted.
        $filter = 'PartitionKey eq\'' . $this->_sessionContainerPartition . '\' and expires lt ' . (time() - $lifeTime);
        try {
            $result = $this->_tableRestProxy->queryEntities($this->_sessionContainer, $filter);
            $entities = $result->getEntities();
            foreach ($entities as $entitiy) {
                $this->_tableRestProxy->deleteEntity($this->_sessionContainer, $this->_sessionContainerParition, $entity->getRowKey());
            }
            return TRUE;
        } catch (ServiceException $e) {
            return FALSE;
        }
    }