@Override
    public Hit clone() {
        Hit hit = (Hit) super.clone();

        hit.fields = fields != null ? new LinkedHashMap<>(fields) : null;
        hit.unmodifiableFieldMap = null;
        if (types != null)
            hit.types = new LinkedHashSet<>(types);
        if (filled != null) {
            hit.setFilledInternal(new HashSet<>(filled));
        }

        return hit;
    }
Compares this hit to another hit
container-search/src/main/java/com/yahoo/search/result/Hit.java