code: ModbusResponse updateResponseWithHeader(ModbusResponse response, boolean ignoreFunctionCode) {
  
          // transfer header data
          response.setHeadless(isHeadless());
          if (!isHeadless()) {
              response.setTransactionID(getTransactionID());
              response.setProtocolID(getProtocolID());
          }
          else {
              response.setHeadless();
          }
          response.setUnitID(getUnitID());
          if (!ignoreFunctionCode) {
              response.setFunctionCode(getFunctionCode());
          }
          return response;
      }
docs: Updates the response with the header information to match the request
  
  @param response Response to update
  @param ignoreFunctionCode True if the function code should stay unmolested
  @return Updated response