docs: public synchronized void startAllRegisteredInformers() {
      if (Collections.isEmptyMap(informers)) {
        return;
      }
      informers.forEach(
          (informerType, informer) -> {
            if (!startedInformers.containsKey(informerType)) {
              startedInformers.put(informerType, informerExecutor.submit(informer::run));
            }
          });
    }