@Override
 public synchronized Map<String, ComponentInfo<Manager>> getManagers() {
   if (_managers.size() == 0) {
     populateManagers();
   }
   return _managers;
 }
  @Override
  protected void populateManagers() {
    // override FOSS SSVM manager
    super.populateManagers();
    addManager("secondary storage vm manager", PremiumSecondaryStorageManagerImpl.class);

    addManager("HA Manager", HighAvailabilityManagerExtImpl.class);
    addManager("VMWareManager", VmwareManagerImpl.class);
    addManager("ExternalNetworkManager", ExternalNetworkDeviceManagerImpl.class);
    addManager("BareMetalVmManager", BareMetalVmManagerImpl.class);
    addManager("ExternalDhcpManager", ExternalDhcpManagerImpl.class);
    addManager("PxeServerManager", PxeServerManagerImpl.class);
    addManager("NetworkUsageManager", NetworkUsageManagerImpl.class);
    addManager("NetappManager", NetappManagerImpl.class);
  }