private ServerBuilder buildServerBuilder(Server server, MetricRegistry metricRegistry) {
        final ServerBuilder serverBuilder = com.linecorp.armeria.server.Server.builder();
        serverBuilder.meterRegistry(DropwizardMeterRegistries.newRegistry(metricRegistry));

        if (armeriaSettings != null) {
            ArmeriaConfigurationUtil.configureServer(serverBuilder, armeriaSettings);
        } else {
            logger.warn("Armeria configuration was null. ServerBuilder is not customized from it.");
        }

        return serverBuilder.blockingTaskExecutor(newBlockingTaskExecutor(), true)
                            .serviceUnder("/", JettyService.of(server));
    }
a helper method to facilitate the signature change in {@link AbstractServerFactory} in release 2.1, where
the 5th {@link AdminEnvironment} param is added.
dropwizard2/src/main/java/com/linecorp/armeria/dropwizard/ArmeriaServerFactory.java