@Override
    public Set<String> getPossibleUserAttributeNames(final PersonAttributeDaoFilter filter) {
        return Set.copyOf(this.backingPerson.getAttributes().keySet());
    }
Provides the ability to define static attributes and values.

@author Misagh Moayyed
@since 7.1.0
core/cas-server-core-authentication-api/src/main/java/org/apereo/cas/authentication/attribute/StubPersonAttributeDao.java