code: @Override
      public void unexportDevices() throws DevFailed {
          xlogger.entry();
          final List<DeviceClassBuilder> clazzToRemove = new ArrayList<DeviceClassBuilder>();
          for (final DeviceClassBuilder clazz : deviceClassList) {
              if (!clazz.getDeviceClass().equals(AdminDevice.class)) {
                  for (final DeviceImpl device : clazz.getDeviceImplList()) {
                      logger.debug("unexport device {}", device.getName());
                      ORBUtils.unexportDevice(device);
                  }
                  clazz.clearDevices();
                  clazzToRemove.add(clazz);
              }
          }
          for (final DeviceClassBuilder deviceClassBuilder : clazzToRemove) {
              deviceClassList.remove(deviceClassBuilder);
          }
          // unregisterServer();
          // deviceClassList.clear();
          xlogger.exit();
      }
docs: Unexport all except admin device
  
  @throws DevFailed