PersistenceContainer container = dataSource.getContainer();
PersistenceProvider provider = dataSource.getProvider();
PersistenceCommonDescriptor config = facet.getConfig();
PersistenceUnitCommon unit = config.createPersistenceUnit();
unit.name(unitName).description(DEFAULT_UNIT_DESC);
unit.transactionType(container.isJTASupported() ? "JTA" : "RESOURCE_LOCAL");
if (provider.getProvider() != null)
{
unit.provider(provider.getProvider());
}