public void addButton(final PlugInContext context) {
   if (!circleButtonAdded) {
     final ToolboxDialog toolbox =
         ((EditingPlugIn) context.getWorkbenchContext().getBlackboard().get(EditingPlugIn.KEY))
             .getToolbox(context.getWorkbenchContext());
     QuasimodeTool quasimodeTool =
         new QuasimodeTool(DrawConstrainedCircleTool.create(toolbox.getContext()));
     quasimodeTool.add(new QuasimodeTool.ModifierKeySpec(true, false, false), null);
     quasimodeTool.add(new QuasimodeTool.ModifierKeySpec(true, true, false), null);
     toolbox.add(quasimodeTool, null);
     toolbox.finishAddingComponents();
     toolbox.validate();
     circleButtonAdded = true;
   }
 }
  public void addButton(final ToolboxDialog toolbox) {
    if (!selectSelectItemsByCircleButtonAdded) {

      MouseEvent event =
          new MouseEvent(
              toolbox, MouseEvent.MOUSE_CLICKED, System.currentTimeMillis(), 0, 0, 0, 1, true);
      toolbox.getContext();
      QuasimodeTool sit =
          new QuasimodeTool(new SelectItemsByCircleTool(toolbox.getContext()))
              .add(new QuasimodeTool.ModifierKeySpec(true, false, false), null);
      sit.mousePressed(event);
      toolbox.add(sit);
      toolbox.finishAddingComponents();
      toolbox.validate();
      selectSelectItemsByCircleButtonAdded = true;
    }
  }