public URI serverUrl() {
        return jettyServer.getURI();
    }
Pluggable hook to customize the admin resources on this server after they have been instantiated and registered
with the given {@link ResourceConfig}. This may be used to, for example, add REST extensions via
{@link #registerRestExtensions(Herder, ResourceConfig)}.
<p>
<em>N.B.: Classes do <b>not</b> need to register the resources provided in {@link #adminResources()} with
the {@link ResourceConfig} parameter in this method; they are automatically registered by the parent class.</em>
@param adminResourceConfig the {@link ResourceConfig} that the server's admin listeners are registered with; never null
connect/runtime/src/main/java/org/apache/kafka/connect/runtime/rest/RestServer.java