用detectron2进行mask rcnn预测时，显示的图片无类别和mask，只有预测分数怎么办

fruits_nuts_metadata = MetadataCatalog.get("fruits_nuts")


if __name__ == "__main__":
    cfg = get_cfg()
    cfg.merge_from_file(
        "/media/dell/新加卷2/downcode/detectron2_train(ubuntu)/configs/COCO-InstanceSegmentation//mask_rcnn_R_50_FPN_3x.yaml"
    )
    cfg.MODEL.WEIGHTS = os.path.join(cfg.OUTPUT_DIR, "model_final.pth")
    print('loading from: {}'.format(cfg.MODEL.WEIGHTS))
    cfg.MODEL.ROI_HEADS.SCORE_THRESH_TEST = 0.5   # set the testing threshold for this model
    cfg.MODEL.ROI_HEADS.NUM_CLASSES = 3
    cfg.DATASETS.TEST = ("fruits_nuts", )
    predictor = DefaultPredictor(cfg)

    data_f = './data/images/2.jpg'
    im = cv2.imread(data_f)
    outputs = predictor(im)
    v = Visualizer(im[:, :, ::-1],
                   metadata=fruits_nuts_metadata,
                   scale=0.8,
                   instance_mode=ColorMode.IMAGE_BW   # remove the colors of unsegmented pixels
                   )
    v = v.draw_instance_predictions(outputs["instances"].to("cpu"))
    img = v.get_image()[:, :, ::-1]
    cv2.imshow('rr', img)
    cv2.waitKey(0)

v.draw_instance_predictions看这个函数，类别没显示而已，mask已经画好在你这图上了，是有的

那怎么修改代码可以把类别显示出来？