def METHOD_NAME(self, roi_feat, bbox_pred):
    """
    Get prediction mask in test stage.
    Args:
        roi_feat (Variable): RoI feature from RoIExtractor.
        bbox_pred (Variable): predicted bbox.
    Returns:
        mask_pred (Variable): Prediction mask with shape
            [N, num_classes, resolution, resolution].
    """
    mask_logits = self._get_output(roi_feat)
    mask_prob = fluid.layers.sigmoid(mask_logits)
    mask_prob = fluid.layers.lod_reset(mask_prob, bbox_pred)
    return mask_prob