@Test
public void testUpdated() throws Exception {

  Dictionary<String, String> properties = new Hashtable<>();
  properties.put(WaveformServiceImpl.WAVEFORM_COLOR_CONFIG_KEY, "blue green 0x2A2A2A 323232CC");
  properties.put(WaveformServiceImpl.WAVEFORM_SPLIT_CHANNELS_CONFIG_KEY, "false");
  properties.put(WaveformServiceImpl.WAVEFORM_SCALE_CONFIG_KEY, "lin");
  ServiceRegistry serviceRegistry = EasyMock.createNiceMock(ServiceRegistry.class);
  EasyMock.expect(serviceRegistry.getHostRegistrations()).andReturn(new ArrayList());
  EasyMock.replay(serviceRegistry);
  WaveformServiceImpl instance = new WaveformServiceImpl();
  instance.setServiceRegistry(serviceRegistry);
  try {
    instance.updated(properties);
    // we can not check private fields but it should not throw any exception
  } catch (Exception e) {
    fail("updated method should not throw any exceptions but has thrown: " + ExceptionUtils.getStackTrace(e));
  }
}