code: boolean isEmpty(String repoFullName) {
      lock.readLock().lock();
      try {
        verifyRepoRegistered(repoFullName);
        return entityListenersByRepo.get(repoFullName).isEmpty();
      } finally {
        lock.readLock().unlock();
      }
    }
docs: Check if a repository has no listeners Repository must be registered
  
  @return boolean