@Override
    protected List<Object> getAttributeValue(final Map<String, List<Object>> resolvedAttributes, final String attributeName, final String mappedAttributeName) {
        return Objects.requireNonNullElseGet(resolvedAttributes.get(mappedAttributeName), List::of);
    }
Return a collection of allowed attributes for the principal, but additionally,
offers the ability to resolve those attributes from a set attributes that provide the value.

@author Misagh Moayyed
@since 7.0.0
core/cas-server-core-authentication-attributes/src/main/java/org/apereo/cas/services/ReturnLinkedAttributeReleasePolicy.java