public IdentityDocument withServiceIdentity(AthenzIdentity serviceIdentity) {
        return new IdentityDocument(
                this.providerUniqueId,
                this.providerService,
                this.configServerHostname,
                this.instanceHostname,
                this.createdAt,
                this.ipAddresses,
                this.identityType,
                this.clusterType,
                this.ztsUrl,
                serviceIdentity,
                this.unknownAttributes);
    }
Represents an unsigned identity document
@author mortent
vespa-athenz/src/main/java/com/yahoo/vespa/athenz/identityprovider/api/IdentityDocument.java