protected:

     BipartiteGraphWrapper() : GraphWrapper<Graph>(0) { }

     void setSFalseTTrueMap(SFalseTTrueMap& _s_false_t_true_map) { 

       s_false_t_true_map=_s_false_t_true_map;

     }

   ///\bug Do not use this while the bipartitemap augmentation 

   /// does not work well.

   template<typename Graph>

   class BipartiteGraph : public BipartiteGraphWrapper<Graph> {

     typedef IterableBoolMap< typename Graph::template NodeMap<int> > 

     SFalseTTrueMap;

     typedef BipartiteGraphWrapper<Graph> Parent;

   protected:

     Graph gr;

     typename Graph::template NodeMap<int> bipartite_map;

     SFalseTTrueMap s_false_t_true_map;

   public:

     typedef typename Parent::Node Node;

     typedef typename Parent::Edge Edge;

     BipartiteGraph() : BipartiteGraphWrapper<Graph>(0), 

 		       gr(), bipartite_map(gr), 

 		       s_false_t_true_map(bipartite_map) { 

       Parent::setGraph(gr); 

       Parent::setSFalseTTrueMap(bipartite_map);

     }

     /// the \c bool parameter which can be \c S_Class or \c T_Class shows 

     /// the color class where the new node is to be inserted.

     void addNode(bool);

     /// A new edge is inserted.

     ///\pre \c tail have to be in \c S_Class and \c head in \c T_Class.

     void addEdge(const Node& tail, const Node& head);

     void erase(const Node&);

     void erase(const Edge&);

     void clear() {

       FOR_EACH_LOC(typename Parent::EdgeIt, e, G) erase(e);

       FOR_EACH_LOC(typename Parent::NodeIt, n, G) erase(n);

     }

   };