        groundtruth_file = os.path.join(DATA_FOLDER, 'gt_test_{}.csv'.format(i))

        with open('{}_{}.json'.format(predictions_file, i), 'r') as f:
            fold = json.load(f)
            folds.append(fold)
            predictions.update(fold)

        ids_fold, gt_fold = shared.load_id2gt(groundtruth_file)

        ids += ids_fold
        groundtruth.update(gt_fold)

    groundtruth_ids = set(ids)
    predictions_ids = set(predictions.keys())
