private void validate(Long id, Todo todo) {
    if (isSameTodo(id, todo)) {
      throw new ForbiddenException("id does not match TODO");
    }

    if (todoService.findOne(id) == null) {
      throw new NotFoundException(String.format("Todo with id %s not found", id));
    }
  }
 @RequestMapping(value = "/todos/{id}", method = RequestMethod.GET)
 public ResponseEntity<Todo> get(@PathVariable Long id) {
   final Todo todo = todoService.findOne(id);
   return new ResponseEntity<>(todo, todo == null ? NOT_FOUND : OK);
 }