### Question:
UserService implements UserDetailsService { @Override public UserDetails loadUserByUsername(final String usernameOrEmail) { EUser u = userRepository.findFirstByUsernameOrEmail(usernameOrEmail, usernameOrEmail); if (u != null) { return u; } throw new UsernameNotFoundException(msg.getMessage(USER_NOT_FOUND)); }  EUser createDefaultUser(); EUser signUp(final EUser u, final EmailStatus emailStatus); EUser signUp(final EUser u, final EmailStatus emailStatus,
                        final RegistrationPrivilege registrationPrivilege); List<Long> addRolesToUser(final Long userId, final Long entityId,
                                     final Iterable<Long> rolesId); List<Long> removeRolesFromUser(final Long userId, final Long entityId, final Iterable<Long> rolesId); @Override UserDetails loadUserByUsername(final String usernameOrEmail); String getUserAuthoritiesForToken(final String usernameOrEmail, final String separator); Map<String, List<BRole>> getRolesForUser(final Long id); List<BRole> getRolesForUserOverEntity(final Long userId, final Long entityId); Long getEntityIdByUser(final EUser u);  }### Answer:
@Test public void loadUserByUsername() { EUser u = userRepository.save(EntityUtil.getSampleUser(random.nextString())); assertNotNull(u); UserDetails su = userService.loadUserByUsername(u.getUsername()); assertNotNull(su); assertEquals(su, u); }