if val == 0 {
		return def
	}
	return val
}

// PerformApplicationHealthCheck Performs the application-provided configuration health check.
// Instead of a heartbeat-based health checks, we only send on a health state change, and this is
// determined by the success & failure threshold provided by the user.
func (w *WorkloadHealthChecker) PerformApplicationHealthCheck(callback func(*ProbeEvent), quit chan struct{}) {
	if w == nil {

				}
				if prev && !want {
					assert.NoError(t, listener.Close())
				}
				<-cont
				prev = want
			}
		}()

		eventNum := atomic.NewInt32(0)
		go tcpHealthChecker.PerformApplicationHealthCheck(func(event *ProbeEvent) {
			if int(eventNum.Load()) >= len(tcpHealthStatuses) {
				return
			}
			if event.Healthy != expectedTCPEvents[eventNum.Load()].Healthy {

	go func() {
		if err := proxy.downstreamGrpcServer.Serve(proxy.downstreamListener); err != nil {
			log.Errorf("failed to accept downstream gRPC connection %v", err)
		}
	}()

	go proxy.healthChecker.PerformApplicationHealthCheck(func(healthEvent *health.ProbeEvent) {
		// Store the same response as Delta and SotW. Depending on how Envoy connects we will use one or the other.
		req := &discovery.DiscoveryRequest{TypeUrl: model.HealthInfoType}