/**
   * The constants used in this Content Widget.
   */
  public static interface CwConstants extends Constants,
      ContentWidget.CwConstants {
    String cwCheckBoxCheckAll();

    String cwCheckBoxDescription();

    String cwCheckBoxFemale();

    String cwCheckBoxMale();

    String cwCheckBoxName();

    String cwCheckBoxUnknown();
  }

  /**
   * An instance of the constants.
   */
  private CwConstants constants;

  /**
   * Initialize this example.
   */
  @Override
  public Widget onInitialize() {
    // Create a vertical panel to align the check boxes
    VerticalPanel vPanel = new VerticalPanel();
    HTML label = new HTML(constants.cwCheckBoxCheckAll());
    label.ensureDebugId("cwCheckBox-label");
    vPanel.add(label);

    // Add a male checkbox
    CheckBox maleCheckBox = new CheckBox(constants.cwCheckBoxMale());
    maleCheckBox.ensureDebugId("cwCheckBox-male");
    vPanel.add(maleCheckBox);
    
    // Add a female checkbox
    CheckBox femaleCheckBox = new CheckBox(constants.cwCheckBoxFemale()); 
    femaleCheckBox.ensureDebugId("cwCheckBox-female");
    vPanel.add(femaleCheckBox);

    // Add one disabled checkbox
    CheckBox disabledCheckBox = new CheckBox(constants.cwCheckBoxUnknown());
    disabledCheckBox.ensureDebugId("cwCheckBox-disabled");
    disabledCheckBox.setEnabled(false);
    vPanel.add(disabledCheckBox);

    // Return the panel of checkboxes
    return vPanel;
  }