_childCache.put(url, children);
_queryCache.put(url, children);
    public HttpUrl getUrlQueryAt(HttpUrl url, int index) {        HttpUrl[] children = (HttpUrl[]) _childCache.get(url);        if (children == null) {            SortedSet childSet = (SortedSet) _urlQueries.get(url);            if (childSet == null)                throw new IndexOutOfBoundsException(url + " has no queries");            if (index >= childSet.size())                throw new IndexOutOfBoundsException(url + " has only " + childSet.size() + " queries, not " + index);            children = ((HttpUrl[]) childSet.toArray(NO_CHILDREN));            _childCache.put(url, children);        }        return children[index];    }