/**
* Begins a transaction (if supported).
* @param string optional savepoint name
* @return void
*/
public function begin($savepoint = NULL)
{
$this->connected || $this->connect();
$event = $this->onEvent ? new Event($this, Event::BEGIN, $savepoint) : NULL;
try {
$this->driver->begin($savepoint);
$event && $this->onEvent($event->done());
} catch (Exception $e) {
$event && $this->onEvent($event->done($e));
throw $e;
}
}