@Override
  public void reload(AppSettings settings) throws IOException {
    if (ClusterSettings.isClusterEnabled(settings)) {
      throw new IllegalStateException("Restart is not possible with cluster mode");
    }
    AppSettings reloaded = settingsLoader.load();
    ensureUnchangedConfiguration(settings.getProps(), reloaded.getProps());
    settings.reload(reloaded.getProps());

    fileSystem.reset();
    logging.configure();
    appState.reset();
  }
@Test
  public void throw_ISE_if_cluster_is_enabled() throws IOException {
    AppSettings settings = new TestAppSettings(ImmutableMap.of(CLUSTER_ENABLED.getKey(), "true"));

    assertThatThrownBy(() -> {
      underTest.reload(settings);

      verifyNoInteractions(logging);
      verifyNoInteractions(state);
      verifyNoInteractions(fs);
    })
      .isInstanceOf(IllegalStateException.class)
      .hasMessage("Restart is not possible with cluster mode");
  }