private int findIndexByIdentity(Item item) {
        int position = 0;
        for (Iterator<Item> i = item.getParent().getItemIterator(); i.hasNext(); ) {
            Item child = i.next();
            if (item == child) {
                return position;
            }
            position++;
        }
        return -1;
    }
Removes this item by identity to ensure we remove the right one if there are multiple
equal items
container-search/src/main/java/com/yahoo/prelude/semantics/engine/Evaluation.java