code: Stream<Entity> updateEntities(String repoFullName, Stream<Entity> entities) {
      lock.readLock().lock();
      try {
        verifyRepoRegistered(repoFullName);
        SetMultimap<Object, EntityListener> entityListeners =
            this.entityListenersByRepo.get(repoFullName);
        return entities.filter(
            entity -> {
              Set<EntityListener> entityEntityListeners = entityListeners.get(entity.getIdValue());
              entityEntityListeners.forEach(entityListener -> entityListener.postUpdate(entity));
              return true;
            });
      } finally {
        lock.readLock().unlock();
      }
    }
docs: Update all registered listeners of the entities
  
  @return Stream<Entity>