private static MongoClientOptions configureMongoOptions() {
    final MongoClientOptions.Builder options = MongoClientOptions.builder();

    for (ApplicationClass clazz : Play.classes.getAssignableClasses(MongoConfigurator.class)) {
      try {
        final MongoConfigurator configurator = (MongoConfigurator) clazz.javaClass.newInstance();
        configurator.configureOptions(options);
      } catch (InstantiationException e) {
        throw new ConfigurationException(
            String.format("failed to create configurator: %s", clazz.name));
      } catch (IllegalAccessException e) {
        throw new ConfigurationException(
            String.format("failed to create configurator: %s", clazz.name));
      }
    }

    return options.build();
  }
 public MongoPersistWriter() {
   this(MongoConfigurator.detectConfiguration(StreamsConfigurator.config.getConfig("mongo")));
 }