### Question:
TppController implements TppRestApi { @Override public ResponseEntity<BankCodeStructure> getBankCodeStructure(String countryCode) { return ResponseEntity.ok(ibanGenerationService.getBankCodeStructure(CountryCode.valueOf(countryCode))); }  @Override void login(String login, String pin); @Override ResponseEntity<Set<Currency>> getCurrencies(); @Override ResponseEntity<Map<CountryCode, String>> getSupportedCountryCodes(); @Override ResponseEntity<BankCodeStructure> getBankCodeStructure(String countryCode); @Override ResponseEntity<String> getRandomTppId(String countryCode); @Override ResponseEntity<Void> register(User user); @Override ResponseEntity<Void> remove(); @Override ResponseEntity<Void> transactions(String accountId); @Override ResponseEntity<Void> account(String accountId); @Override ResponseEntity<Void> user(String userId); @Override ResponseEntity<Void> revert(RevertRequestTO revertRequest);  }### Answer:
@Test void getBankCodeStructure() { when(ibanGenerationService.getBankCodeStructure(any())).thenReturn(getBankCode()); ResponseEntity<BankCodeStructure> response = tppController.getBankCodeStructure("DE"); assertTrue(response.getStatusCode().is2xxSuccessful()); assertEquals(8, Objects.requireNonNull(response.getBody()).getLength()); assertEquals(EntryCharacterType.n, response.getBody().getType()); }