docs: @Override
    public FileBasedPersistenceContext createPersistenceContextWithin(PersistenceSpaceIdentifier<?> identifier, String name)
        throws CachePersistenceException {
      if(getPersistenceSpace(identifier) == null) {
        throw newCachePersistenceException(identifier);
      }
      return new DefaultFileBasedPersistenceContext(
          FileUtils.createSubDirectory(((DefaultPersistenceSpaceIdentifier)identifier).persistentSpaceId.getRoot(), name));
    }