public String getAlternativeId() {
        var alternativeId = getUsername() + "@" + getOrganisationId();
        return alternativeId.toLowerCase();
    }
An alternative identifier to uniquely identify a HiOrg-Server user.

@return username and the organisation id, joined by an at-sign, lowercase
pac4j-oauth/src/main/java/org/pac4j/oauth/profile/hiorgserver/HiOrgServerProfile.java