ping property
ping If set to true (ping=1), the request will be a Heartbeat request which will not track any new activity (such as a new visit, new action or new goal). The heartbeat request will only update the visit's total time to provide accurate "Visit duration" metric when this parameter is set. It won't record any other data. This means by sending an additional tracking request when the user leaves your site or app with ping set to true (&ping=1), you fix the issue where the time spent of the last page visited is reported as 0 seconds.
Implementation
bool? ping;