code: @Override
      public void register(CareWebShell shell, ElementBase owner, boolean register) {
          if (register) {
              ElementPlugin plugin = (ElementPlugin) owner;
              Button button = new Button(getCaption());
              button.setName(getId());
              button.setHint(getHint());
              button.setImage(getIcon());
              ActionUtil.addAction(button, getAction());
              plugin.addToolbarComponent(button);
              plugin.registerId(getId(), button);
          }
      }
docs: Registers/unregisters a button resource.
  
  @param shell The running shell.
  @param owner Owner of the resource.
  @param register If true, register the resource. If false, unregister it.