public async Task <IActionResult> GetAccountByIban(string accountIban)
        {
            var accountResponse = await customerAccountsService.GetAccountAsync(accountIban);

            if (accountResponse == null)
            {
                return(NotFound());
            }

            return(Ok(accountResponse));
        }
        public async Task GetAccountByIban_WithAccountIbanExsits_ReturnStatusCodeOK()
        {
            // Arrange
            var accountIban = "AAAA";

            var accountResponse = new AccountResponse
            {
                AccountIban = "AAAA",
                Balance     = 1000
            };

            customerAccountsService
            .GetAccountAsync(Arg.Any <string>())
            .Returns(Task.FromResult(accountResponse));

            // Act
            var actionResult = await accountsController.GetAccountByIban(accountIban);

            var objectResult = actionResult as OkObjectResult;

            // Assert
            Assert.NotNull(objectResult);
            Assert.Equal(objectResult.StatusCode, (int)System.Net.HttpStatusCode.OK);
        }