def groundtruth_lists(self, field):
    """Access list of groundtruth tensors.

    Args:
      field: a string key, options are
        fields.BoxListFields.{boxes,classes,masks,keypoints,
        keypoint_visibilities, densepose_*, track_ids,
        temporal_offsets, track_match_flags}
        fields.InputDataFields.is_annotated.

    Returns:
      a list of tensors holding groundtruth information (see also
      provide_groundtruth function below), with one entry for each image in the
      batch.
    Raises:
      RuntimeError: if the field has not been provided via provide_groundtruth.
    """
    if field not in self._groundtruth_lists:
      raise RuntimeError('Groundtruth tensor {} has not been provided'.format(
          field))
    return self._groundtruth_lists[field]
Access list of groundtruth tensors.

    Args:
      field: a string key, options are
        fields.BoxListFields.{boxes,classes,masks,keypoints,
        keypoint_visibilities, densepose_*, track_ids,
        temporal_offsets, track_match_flags}
        fields.InputDataFields.is_annotated.

    Returns:
      a list of tensors holding groundtruth information (see also
      provide_groundtruth function below), with one entry for each image in the
      batch.
    Raises:
      RuntimeError: if the field has not been provided via provide_groundtruth.
    
inference_api/src/main/object_detection/core/model.py