private long calculateConjunctionId() {
        long posHash = 0;
        for (long feature : features) {
            posHash ^= feature;
        }
        long negHash = 0;
        for (long feature : negatedFeatures) {
            negHash ^= feature;
        }
        return (posHash + 3 * negHash) | 1;
    }
K value - number of non-negated operands
predicate-search/src/main/java/com/yahoo/search/predicate/index/conjunction/IndexableFeatureConjunction.java