code: public static Canvas createWidget(String key) {
  		WidgetBuilder builder = WIDGETBUILDERS.get(key);
  		if (null == builder) {
  			return null;
  		}
  		return builder.createWidget();
  	}
docs: Create a widget of given type.
  
  @param key
  key of widgettype
  @return widget (canvas) or null when key not found