NamespaceFacade return null if namespace is empty

/**
 * Return the current namespace or "" if none
 *
 * @return namespace
 */
public String getNamespace();

RetryPolicy policy = ...;
CuratorFramework client = CuratorFrameworkFactory.newClient("connectionString", policy);
CuratorFramework clientWithNamespaceFacade = client.usingNamespace(null);
clientWithNamespaceFacade.getNamespace(); // <- expected "", but got null