// policy association.
//
// - inherited from "virtual" parent - this is the case for AssumeRoleWithLDAP
// where the parent user is the DN of the actual LDAP user. The parent user
// itself cannot login, but the policy associated with them determines the base
// policy for the STS credential. The policy mapping can be updated by the
// administrator.
//
// - from `Subject.CommonName` field from the STS request for