@Test
public void testModifyConfig() throws IOException {

  ConfigType configType = mock(ConfigType.class);
  Map<String, Map<String, String>> mockResult = mock(Map.class);
  Map<String, String> config = new HashMap<String, String>();
  config.put("fs.trash.interval", "350");
  config.put("ipc.client.connection.maxidletime", "30000");
  when(configType.getName()).thenReturn(CORE_SITE);
  when(mockResult.get(CORE_SITE)).thenReturn(config);
  when(client.getServiceConfigMap(CORE_SITE)).thenReturn(mockResult);
  configCommands.modifyConfig(configType, "fs.trash.interval", "510");
  Map<String, String> config2 = new HashMap<String, String>();
  config2.put("fs.trash.interval", "510");
  config2.put("ipc.client.connection.maxidletime", "30000");
  verify(client).modifyConfiguration(CORE_SITE, config2);
}