import tensorflow as tf

      ignored_matches: a bool tensor of shape of [batch, N], representing
        whether each box is an ignored matches or not. An ignored matches is the
        match that is neither positive or negative.
    """
    matched_gt_boxes, matched_gt_classes, matched_gt_indices, matched_iou, _ = (
        box_ops.box_matching(boxes, gt_boxes, gt_classes))

    positive_matches = tf.greater(
        matched_iou, self._config_dict['foreground_iou_threshold'])
    negative_matches = tf.logical_and(
        tf.greater_equal(
            matched_iou, self._config_dict['background_iou_low_threshold']),
        tf.less(
            matched_iou, self._config_dict['background_iou_high_threshold']))
