@Override
    public DefaultServiceConfigSetters serviceWorkerGroup(EventLoopGroup serviceWorkerGroup,
                                                          boolean shutdownOnStop) {
        this.serviceWorkerGroup = requireNonNull(serviceWorkerGroup, "serviceWorkerGroup");
        if (shutdownOnStop) {
            shutdownSupports.add(ShutdownSupport.of(serviceWorkerGroup));
        }
        return this;
    }
A default implementation of {@link ServiceConfigSetters} that stores service related settings
and provides a method {@link DefaultServiceConfigSetters#toServiceConfigBuilder(Route, String, HttpService)}
to build {@link ServiceConfigBuilder}.
core/src/main/java/com/linecorp/armeria/server/DefaultServiceConfigSetters.java