code: @Override
      public HandlerRegistration addChangeHandler(final ChangeHandler changeHandler) {
          ValueChangeHandler valueChangeHandler = new ValueChangeHandler() {
              @Override
              public void onValueChange(ValueChangeEvent valueChangeEvent) {
                  changeHandler.onChange(null);
              }
          };
          for(CheckBox checkBox : checkBoxes){
              checkBox.addValueChangeHandler(valueChangeHandler);
          }
          return null;
  
      }
docs: TODO: This is an eyesore, Natxo needs to clean this