* JUnit5 with Mockito using @ExtendWith * rename method: givenUserWithExistingName_whenSaveUser_thenGiveUsernameAlreadyExistsError rename this class according to the standard -- UserServiceUnitTest.java
* JUnit5 with Mockito using @ExtendWith * rename method: givenUserWithExistingName_whenSaveUser_thenGiveUsernameAlreadyExistsError rename this class according to the standard -- UserServiceUnitTest.java