code: func (c *Connection) ReceiveTickerInterval() int64 {
  	if c.hbd == nil {
  		return 0
  	}
  	return c.hbd.rti / 1000000
  }
docs: /*
  	ReceiveTickerInterval returns any heartbeat receive ticker interval in ms.
  	A return value of zero means no heartbeats are being received.
  */