@Override
  public boolean remRole(Role role) {
    return Objects.nonNull(roles.remove(role));
  }
@Test
  void remRole() {
    var core = new CustomerCore();
    core.addRole(Role.BORROWER);

    var bRole = core.getRole(Role.BORROWER, BorrowerRole.class);
    assertTrue(bRole.isPresent());

    assertTrue(core.remRole(Role.BORROWER));

    var empt = core.getRole(Role.BORROWER, BorrowerRole.class);
    assertFalse(empt.isPresent());
  }