@Override
    public SegmentItem clone() {
        SegmentItem copy;
        synchronized(this) {
            boolean tmpLock = locked;

            locked = false;
            copy = (SegmentItem) super.clone();
            locked = tmpLock;
            copy.locked = tmpLock;
        }
        return copy;
    }
Return a deep copy of this object
container-search/src/main/java/com/yahoo/prelude/query/SegmentItem.java