code: protected Component newAddAllComponent() {
          return new PaletteButton("addAllButton") {
              private static final long serialVersionUID = 1L;
  
              protected void onComponentTag(ComponentTag tag) {
                  super.onComponentTag(tag);
                  tag.getAttributes().put("onclick", getAddAllOnClickJS());
              }
          };
      }
docs: factory method for the addAll component
  
  @return addAll component