@Override
	protected boolean getConfiguredLeaf() {
		return true;
	}

public class BaubarkeitForm extends AbstractForm {

  public GroupBox getGroupBox() {
    return getFieldByClass(GroupBox.class);
  }

  public class MainBox extends AbstractGroupBox {

    @Order(1000)
    @ClassId("f8727d17-a92c-4a48-ac66-e9c198578a67")
    public class GroupBox extends AbstractGroupBox {

      // ...
    }
  }

  public void startView() {
    startInternal(new ViewHandler());
  }

  public void startModify() {
    startInternal(new ModifyHandler());
  }

  public class ViewHandler extends AbstractFormHandler {

    @Override
    protected void execLoad() {
      getGroupBox().setLabel("View data");
    }
  }

  public class ModifyHandler extends AbstractFormHandler {

    @Override
    protected void execLoad() {
      getGroupBox().setLabel("Modify data");
    }
  }
}

public class BaubarkeitPage extends AbstractPageWithNodes {

  @Override
  protected String getConfiguredTitle() {
    return "Baubarkeit";
  }

// *** Not necessary if child page is activated automatically: ***
//
//  @Override
//  protected Class<? extends IForm> getConfiguredDetailForm() {
//    return BaubarkeitForm.class;
//  }
//
//  @Override
//  protected void startDetailForm() {
//    ((BaubarkeitForm) getDetailForm()).startView();
//  }

  @Override
  protected void execCreateChildPages(List<IPage<?>> pageList) {
    pageList.add(new BaubarkeitModifyPage());
  }

  @Override
  protected void execPageActivated() {
    setExpanded(true);
    // Schedule automatic child selection to allow the current selection to be fully completed
    ModelJobs.schedule(new IRunnable() {
      @Override
      public void run() {
        getTree().selectNode(getChildNode(0));
      }
    }, ModelJobs.newInput(ClientRunContexts.copyCurrent()));
  }
}

public class BaubarkeitModifyPage extends AbstractPageWithNodes {

  @Override
  protected String getConfiguredTitle() {
    return "Baubarkeit modifizieren";
  }

  @Override
  protected boolean getConfiguredLeaf() {
    return true;
  }

  @Override
  protected Class<? extends IForm> getConfiguredDetailForm() {
    return BaubarkeitForm.class;
  }

  @Override
  protected void startDetailForm() {
    ((BaubarkeitForm) getDetailForm()).startModify();
  }
}

	@Override
	protected void execPageActivated() {
		setExpanded(true);
		// Schedule automatic child selection to allow the current selection to
		// be fully completed
		ModelJobs.schedule(() -> getTree().selectNode(getChildNode(0)),
				ModelJobs.newInput(ClientRunContexts.copyCurrent()));
	}