function closeDataResponse(
    address seller,
    bool transactionCompleted
  ) public onlyOwner validAddress(seller) returns (bool) {
    require(orderStatus != OrderStatus.TransactionCompleted);
    require(transactionCompletedAt == 0);
    require(hasSellerBeenAccepted(seller));
    require(sellerInfo[seller].status == DataResponseStatus.DataResponseAdded);

    sellerInfo[seller].status = transactionCompleted
      ? DataResponseStatus.TransactionCompleted
      : DataResponseStatus.RefundedToBuyer;
    sellerInfo[seller].closedAt = uint32(block.timestamp);
    return true;
  }