docs: public synchronized <ApiType, ApiListType> SharedIndexInformer<ApiType> sharedIndexInformerFor(
        Function<CallGeneratorParams, Call> callGenerator,
        Class<ApiType> apiTypeClass,
        Class<ApiListType> apiListTypeClass,
        long resyncPeriodInMillis) {
      ListerWatcher<ApiType, ApiListType> listerWatcher =
          listerWatcherFor(callGenerator, apiTypeClass, apiListTypeClass);
      SharedIndexInformer<ApiType> informer =
          new DefaultSharedIndexInformer<ApiType, ApiListType>(
              apiTypeClass, listerWatcher, resyncPeriodInMillis);
      this.informers.put(TypeToken.get(apiTypeClass).getType(), informer);
      return informer;
    }