code: protected static Resources getDefaultResources() { // NOPMD it's thread save!
      if (SelectBoxWithIconInputWidget.defaultResource == null) {
        synchronized (Resources.class) {
          if (SelectBoxWithIconInputWidget.defaultResource == null) {
            SelectBoxWithIconInputWidget.defaultResource = GWT.create(Resources.class);
          }
        }
      }
      return SelectBoxWithIconInputWidget.defaultResource;
    }
docs: get default resource, if not set, create one.
  
  @return default resource.