// ClassLoaderServiceImpl#fromConfigSettings
properties.put( AvailableSettings.ENVIRONMENT_CLASSLOADER, osgiClassLoader );
osgiClassLoader.addBundle( requestingBundle );
Ejb3Configuration cfg = new Ejb3Configuration();
Ejb3Configuration configured = cfg.configure( persistenceUnitName, properties );
return configured != null ? configured.buildEntityManagerFactory( getBuilder( cfg, properties ) ) : null;
}