docs: public static Protos.PaymentRequest.Builder createPaymentRequest(NetworkParameters params,
              List<Protos.Output> outputs, @Nullable String memo, @Nullable String paymentUrl,
              @Nullable byte[] merchantData) {
          final Protos.PaymentDetails.Builder paymentDetails = Protos.PaymentDetails.newBuilder();
          paymentDetails.setNetwork(params.getPaymentProtocolId());
          for (Protos.Output output : outputs)
              paymentDetails.addOutputs(output);
          if (memo != null)
              paymentDetails.setMemo(memo);
          if (paymentUrl != null)
              paymentDetails.setPaymentUrl(paymentUrl);
          if (merchantData != null)
              paymentDetails.setMerchantData(ByteString.copyFrom(merchantData));
          paymentDetails.setTime(Utils.currentTimeSeconds());
  
          final Protos.PaymentRequest.Builder paymentRequest = Protos.PaymentRequest.newBuilder();
          paymentRequest.setSerializedPaymentDetails(paymentDetails.build().toByteString());
          return paymentRequest;
      }