docs: function style(extra, dataIndexInside) {
          dataIndexInside == null && (dataIndexInside = currDataIndexInside);
          updateCache(dataIndexInside);
  
          var itemStyle = currItemModel.getModel(ITEM_STYLE_NORMAL_PATH).getItemStyle();
  
          currVisualColor != null && (itemStyle.fill = currVisualColor);
          var opacity = data.getItemVisual(dataIndexInside, 'opacity');
          opacity != null && (itemStyle.opacity = opacity);
  
          graphicUtil.setTextStyle(itemStyle, currLabelNormalModel, null, {
              autoColor: currVisualColor,
              isRectText: true
          });
  
          itemStyle.text = currLabelNormalModel.getShallow('show')
              ? zrUtil.retrieve2(
                  customSeries.getFormattedLabel(dataIndexInside, 'normal'),
                  getDefaultLabel(data, dataIndexInside)
              )
              : null;
  
          extra && zrUtil.extend(itemStyle, extra);
          return itemStyle;
      }