docs: @Override
      public final JcrRepository getRepository( String repositoryName ) throws NoSuchRepositoryException {
          CheckArg.isNotEmpty(repositoryName, "repositoryName");
          checkRunning();
  
          final Lock lock = this.lock.readLock();
          try {
              lock.lock();
              JcrRepository repository = repositories.get(repositoryName);
              if (repository == null) {
                  throw new NoSuchRepositoryException(JcrI18n.repositoryDoesNotExist.text(repositoryName));
              }
              return repository;
          } finally {
              lock.unlock();
          }
      }