def _process_groundtruth_boxes(self, groundtruth_box_tuples):
    """Pre-processes boxes before adding them to the VRDDetectionEvaluation.

    Phrase detection and Relation detection subclasses re-implement this method
    depending on the task.

    Args:
      groundtruth_box_tuples:  A numpy array of structures with the shape
        [M, 1], each structure containing the same number of named bounding
        boxes. Each box is of the format [y_min, x_min, y_max, x_max] (see
        datatype vrd_box_data_type, single_box_data_type above).
    """
    raise NotImplementedError(
        '_process_groundtruth_boxes method should be implemented in subclasses'
        'of VRDDetectionEvaluator.')
Pre-processes boxes before adding them to the VRDDetectionEvaluation.

    Phrase detection and Relation detection subclasses re-implement this method
    depending on the task.

    Args:
      groundtruth_box_tuples:  A numpy array of structures with the shape
        [M, 1], each structure containing the same number of named bounding
        boxes. Each box is of the format [y_min, x_min, y_max, x_max] (see
        datatype vrd_box_data_type, single_box_data_type above).
    
inference_api/src/main/object_detection/utils/vrd_evaluation.py