String name = pu.getName();
pu.setProperty(PersistenceUnitProperties.METADATA_SOURCE, new MetadataSource(pu));
SEPersistenceUnitInfo puInfo = (SEPersistenceUnitInfo) pu.getPersistenceUnitInfo();
JPAInitializer initializer = new PersistenceProvider().getInitializer(name, null);
Map<String, Object> props = new HashMap<String, Object>();
String uniqueName = initializer.createUniquePersistenceUnitName(puInfo);
String sessionName = EntityManagerSetupImpl.getOrBuildSessionName(props, puInfo, uniqueName);