sleep := unit * time.Duration(1<<attempt)
		if sleep > cap {
			sleep = cap
		}
		sleep -= time.Duration(r.Float64() * float64(sleep-unit))
		return sleep
	}
}

func (c *Client) runHealthCheck() bool {
	// Start goroutine that will attempt to reconnect.
	// If server is already trying to reconnect this will have no effect.
	if c.HealthCheckFn != nil && atomic.CompareAndSwapInt32(&c.connected, online, offline) {