private ObjectName generateObjectName() {
final ObjectNameBuilder jmxName = new ObjectNameBuilder("openejb.management");
jmxName.set("ObjectType", "persistence-unit");
jmxName.set("PersistenceUnit", getPUname());
objectName = jmxName.build();
final MBeanServer server = LocalMBeanServer.get();
if (server.isRegistered(objectName)) { // if 2 pu have the same name...a bit uglier but unique
jmxName.set("PersistenceUnit", getPUname() + "(" + getId() + ")");
objectName = jmxName.build();