public IActionResult Run(
            [HttpTrigger(AuthorizationLevel.Anonymous, "get", Route = FunctionConstants.GetItemsOfTodoListFunction + "{listId}")]
            HttpRequest req, string listId)
        {
            var user = _authService.GetClientPrincipalFromRequest(req);

            if (!_todoListService.CanUserAccessList(user, listId))
            {
                return(new UnauthorizedResult());
            }

            if (string.IsNullOrEmpty(listId))
            {
                return(new BadRequestErrorMessageResult("Id cannot be empty"));
            }

            var todoList = _todoItemService.GetAllForListId(listId);

            return(new OkObjectResult(_mapper.Map <IEnumerable <TodoItemDto> >(todoList)));
        }