public ServerBuilder withVirtualHost(String hostnamePattern,
                                         Consumer<? super VirtualHostBuilder> customizer) {
        final VirtualHostBuilder virtualHostBuilder = findOrCreateVirtualHostBuilder(hostnamePattern);
        requireNonNull(customizer, "customizer");
        customizer.accept(virtualHostBuilder);
        virtualHostBuilders.add(virtualHostBuilder);
        return this;
    }
Configures a {@link VirtualHost} with the {@code customizer}.
core/src/main/java/com/linecorp/armeria/server/ServerBuilder.java