def METHOD_NAME(box_scores, iou_threshold, top_k=-1, candidate_size=200):
    """
    Args:
        box_scores (N, 5): boxes in corner-form and probabilities.
        iou_threshold: intersection over union threshold.
        top_k: keep top_k results. If k <= 0, keep all the results.
        candidate_size: only consider the candidates with the highest scores.
    Returns:
         picked: a list of indexes of the kept boxes
    """
    scores = box_scores[:, -1]
    boxes = box_scores[:, :-1]
    picked = []
    _, indexes = scores.sort(descending=True)
    indexes = indexes[:candidate_size]
    while len(indexes) > 0:
        current = indexes[0]
        picked.append(current.item())
        if 0 < top_k == len(picked) or len(indexes) == 1:
            break
        current_box = boxes[current, :]
        indexes = indexes[1:]
        rest_boxes = boxes[indexes, :]
        iou = iou_of(
            rest_boxes,
            current_box.unsqueeze(0),
        )
        indexes = indexes[iou <= iou_threshold]
    return box_scores[picked, :]