docs: private Response query(ChaincodeStub stub, List<String> args) {
          if (args.size() != 1) {
              return newErrorResponse("Incorrect number of arguments. Expecting name of the person to query");
          }
          String key = args.get(0);
          //byte[] stateBytes
          String val	= stub.getStringState(key);
          if (val == null) {
              return newErrorResponse(String.format("Error: state for %s is null", key));
          }
          _logger.info(String.format("Query Response:\nName: %s, Amount: %s\n", key, val));
          return newSuccessResponse(val, ByteString.copyFrom(val, UTF_8).toByteArray());
      }