@RequestMapping(value = "/{invoiceId}/control-letters/{controlLetterId}/rows/{id}")
  public String showControlLetterRow(
      @PathVariable("invoiceId") int invoiceId,
      @PathVariable("controlLetterId") int controlLetterId,
      @PathVariable("id") int id,
      Model model) {

    ControlLetterRow controlLetterRow = controlLetterRowService.find(id);
    if (controlLetterRow == null) throw new ResourceNotFoundException();
    controlLetterRow.setControlLetterId(controlLetterId);

    List<Employee> employees = employeeService.findAll(Employee.EmployeePosition.CONDUCTOR.getId());
    List<Route> routes = routeService.findAll();

    model.addAttribute("routes", routes);
    model.addAttribute("employees", employees);
    model.addAttribute("controlLetterRow", controlLetterRow);
    model.addAttribute("invoiceId", invoiceId);

    return "controlLetterRow/edit";
  }