How to send a heartbeat?

[389103326]

I use the default keepalive value(60), and set reconnectPeriod 2000，frequently receive offline event, I guess need to send heartbeat after the keepalive timeend. But I can't find a method to send a heartbeat, I find pingResp is a property.

[robertsLando]

open an issue and fill the required fields please. I think you may be using an old MQTTjs version