ProtoSession protoSession = context.protoSession;
        for (PropertyContributor propertyContributor : context.lookup
                .lookup(PropertyContributorsHolder.class)
                .getPropertyContributors()
                .values()) {
            protoSession = protoSession.toBuilder()
                    .withUserProperties(propertyContributor.contribute(protoSession))
                    .build();
        }