code: public EntityManager createDefaultEntityManager(String namespace) {
      ConnectionParameters parameters = new ConnectionParameters();
      parameters.setNamespace(namespace);
      return createEntityManager(parameters);
    }
docs: Creates and returns a new {@link EntityManager} using the default options.
  
  @param namespace
  the namespace to work with (for multitenancy)
  
  @return a new {@link EntityManager} using the default options.