return ctx
	}
	return srv
}

// UseCustomLogger use customized logger for this HTTP *Server
func (srv *Server) UseCustomLogger(l *log.Logger) *Server {
	srv.ErrorLog = l
	return srv
}

// UseTCPOptions use custom TCP options on raw socket
func (srv *Server) UseTCPOptions(opts TCPOptions) *Server {
	srv.TCPOptions = opts
	return srv
}

	if authType == prometheusPublic {
		authFn = NoAuthMiddleware
	}

	metricGroups := newMetricGroups(registry)

	return &metricsV3Server{
		registry: registry,
		opts: promhttp.HandlerOpts{
			ErrorLog:            promLogger{},
			ErrorHandling:       promhttp.HTTPErrorOnError,
			Registry:            registry,
			MaxRequestsInFlight: 2,
		},
		authFn: authFn,

		metricsData: metricGroups,
	}
}