code: public void removeValue() {
  
          if (!isSimpleValue()) {
              m_hasValue = false;
              m_widgetHolder.clear();
              generateLabel();
          } else {
              // only deactivate the widget and restore the default value
              m_widget.setActive(false);
              m_widget.setValue("");
              addActivationHandler();
          }
          addStyleName(formCss().emptyValue());
          removeValidationMessage();
      }
docs: Removes the value.<p>