Orthogonal range emptiness queries with CGAL::Range_tree_2

I have a question about implementing orthogonal range emptiness queries in CGAL using CGAL::Range_tree_2 type. The member function window_query() performs reporting those points, which lie in a given query axis-parallel rectangle, inserting them using an std::back_inserter function. In the range emptiness queries one should only report if a query rectangle is empty or not. Thus, applying window_query() function leads to unnecessary time overhead. Is there any more efficient way to implement range emptiness queries in CGAL ?