### Question:
UsersJdbcAuthzRepository extends AbstractJdbcRepository implements UsersAuthzRepository { @Override public Roles findRolesByGuid(String guid) { final List<Roles> list = this.jdbcTemplate.query(" select * from roles where guid = ?", rolesRowMapper, guid); return list.isEmpty() ? null : list.get(0); }  @Override List<Users> findUsersByUsername(String username); @Override List<Roles> findAvailableRolesList(); @Override Users findByUsername(String username); @Override int saveUsers(final Users users); @Override Roles findRolesByGuid(String guid); @Override void insertUserRoles(final int userId, final int rolesId); @Override List<Roles> findUsersRolesList(String usersGuid); @Override List<String> findPermissionsByRoles(String rolesGuid);  }### Answer:
@Test public void findRolesByGuid() throws Exception { final Roles roles = usersJdbcRepository.findRolesByGuid(GuidGenerator.generate()); assertNull(roles); }