public static Authenticator create() {
    ServiceConfigFetcher fetcher = ServiceConfigFetcher.create();
    Service service = fetcher.fetch();
    if (!service.hasAuthentication()) {
      throw new IllegalArgumentException("Authentication is not defined in service config");
    }
    return create(service.getAuthentication(), Clock.SYSTEM);
  }
public static Authenticator create ( ) { ServiceConfigFetcher fetcher = ServiceConfigFetcher . create ( ) ; Service service = fetcher . fetch ( ) ; if ( ! service . hasAuthentication ( ) ) { throw new IllegalArgumentException ( "Authentication is not defined in service config" ) ; } return create ( service . getAuthentication ( ) , Clock . SYSTEM ) ; }
Create an instance of {@link Authenticator} using the service configuration fetched from Google
Service Management APIs.

@return an {@code Authenticator}
@throws java.lang.IllegalArgumentException if the authentication message is not defined in the
fetched service config.