'Convert predicted output tensors to final detections. Unused.
Args:
prediction_dict: a dictionary holding prediction tensors.
**params: Additional keyword arguments for specific implementations of
DetectionModel.
Returns:
detections: a dictionary with empty fields.'

def postprocess(self, prediction_dict, **params):

    return {'detection_boxes': None, 'detection_scores': None, 'detection_classes': None, 'num_detections': None}
