@Override
    protected int onCmp(ResultNode rhs) {
        if (classId != rhs.getClassId()) {
            return (classId - rhs.getClassId());
        }
        IntegerBucketResultNode b = (IntegerBucketResultNode)rhs;
        if (from < b.from) return -1;
        if (from > b.from) return 1;
        if (to < b.to) return -1;
        if (to > b.to) return 1;
        return 0;
    }
Obtain the bucket end

@return bucket end
searchlib/src/main/java/com/yahoo/searchlib/expression/IntegerBucketResultNode.java