### Question:
TppController implements TppRestApi { @Override public ResponseEntity<Void> user(String userId) { return dataRestClient.user(userId); }  @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 user() { when(dataRestClient.user(anyString())).thenReturn(ResponseEntity.ok().build()); ResponseEntity<Void> result = tppController.user(USER_ID); assertEquals(HttpStatus.OK, result.getStatusCode()); }