code: def load(self, add_gt=True, add_mask=False):
          
          if add_mask:
              assert add_gt
          with timed_operation('Load Groundtruth Boxes for {}'.format(self.name)):
              img_ids = self.coco.getImgIds()
              img_ids.sort()
              # list of dict, each has keys: height,width,id,file_name
              imgs = self.coco.loadImgs(img_ids)
  
              for img in tqdm.tqdm(imgs):
                  img['image_id'] = img.pop('id')
                  self._use_absolute_file_name(img)
                  if add_gt:
                      self._add_detection_gt(img, add_mask)
              return imgs
docs: Args:
              add_gt: whether to add ground truth bounding box annotations to the dicts
              add_mask: whether to also add ground truth mask
  
          Returns:
              a list of dict, each has keys including:
                  'image_id', 'file_name',
                  and (if add_gt is True) 'boxes', 'class', 'is_crowd', and optionally
                  'segmentation'.