private boolean testMembership(Predicate<Value> test, Context context) {
        for (ExpressionNode setValue : setValues) {
            if (test.test(setValue.evaluate(context)))
                return true;
        }
        return false;
    }
Returns an immutable list of the values of the set
searchlib/src/main/java/com/yahoo/searchlib/rankingexpression/rule/SetMembershipNode.java