### Question:
JsonUserRepository implements UserRepository { @Override public UserDTO firstUser() { LOGGER.info("fetching firstUser"); return users.get(0); }  @Override List<UserDTO> fetchAllUsers(); @Override UserDTO firstUser(); @Override UserDTO userByFirstNameAndLastName(String firstName, String lastName);  }### Answer:
@Test public void testFirstUser() { assertThat(repo.firstUser().getUserName(), is(equalTo("aha"))); }