@Test
  public void testExecuteForNullResult() {

    ResourceService resourceService = Mockito.mock(ResourceService.class);

    try {
      Mockito.when(resourceService.discoverCluster(addClusterCmd)).thenReturn(null);
    } catch (ResourceInUseException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    } catch (IllegalArgumentException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    } catch (DiscoveryException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }

    addClusterCmd._resourceService = resourceService;

    try {
      addClusterCmd.execute();
    } catch (ServerApiException exception) {
      Assert.assertEquals("Failed to add cluster", exception.getDescription());
    }
  }
  @Test
  public void testExecuteForEmptyResult() {

    ResourceService resourceService = Mockito.mock(ResourceService.class);
    addClusterCmd._resourceService = resourceService;

    try {
      addClusterCmd.execute();
    } catch (ServerApiException exception) {
      Assert.assertEquals("Failed to add cluster", exception.getDescription());
    }
  }
  @Test
  public void testExecuteForResult() throws Exception {

    resourceService = Mockito.mock(ResourceService.class);
    responseGenerator = Mockito.mock(ResponseGenerator.class);

    addClusterCmd._resourceService = resourceService;
    addClusterCmd._responseGenerator = responseGenerator;

    Cluster cluster = Mockito.mock(Cluster.class);
    Cluster[] clusterArray = new Cluster[] {cluster};

    Mockito.when(resourceService.discoverCluster(addClusterCmd))
        .thenReturn(Arrays.asList(clusterArray));

    addClusterCmd.execute();
  }