public function commit($savepoint = NULL)
{
$this->connected || $this->connect();
$event = $this->onEvent ? new Event($this, Event::COMMIT, $savepoint) : NULL;
try {
$this->driver->commit($savepoint);
$event && $this->onEvent($event->done());
} catch (Exception $e) {
$event && $this->onEvent($event->done($e));
throw $e;
}
}