Doctrine\DBAL\Connection::createSavepoint PHP Method

    public function createSavepoint($savepoint)
    {
        if (!$this->getDatabasePlatform()->supportsSavepoints()) {
            throw ConnectionException::savepointsNotSupported();
        }
        $this->_conn->exec($this->platform->createSavePoint($savepoint));
    }

 protected function performCommit($identifier = NULL)
 {
     if ($identifier === NULL) {
         return $this->conn->commit();
     }
     $this->conn->createSavepoint($identifier);
 }