code: protected void previewNativeEvent(NativePreviewEvent event) {
  
          Event nativeEvent = Event.as(event.getNativeEvent());
          if ((nativeEvent.getTypeInt() == Event.ONCLICK)) {
              EventTarget target = nativeEvent.getEventTarget();
              if (!Element.is(target)) {
                  return;
              }
              Element element = Element.as(target);
              if (!m_time.getElement().isOrHasChild(element)) {
                  m_time.blur();
              }
          }
      }
docs: Blurs the time box if the user clicks outside of it.<p>
  
  @param event the native preview event