Obtain culprit from Sentry event in PHP

I’m trying to filter the events the PHP application sends to sentry by defining

'before_send' => function (\Sentry\Event $event) { }

I get the $event object all right, but I can’t find a way to get culprit or location information that I can see at sentry report (altered screenshot of json data stored about the event attached).

Unfortunately, the documentation is not very helpful - or at least I was not able to find correct methods to obtain any of those 2 pieces.

Any ideas on what I’m missing? Looping through the frames doesn’t look like a correct approach in my case.