///

         ///

         UndirEdgeIt(Invalid) { }

         UndirEdgeIt(Invalid) { }

         /// This constructor sets the iterator to the first edge.

         /// This constructor sets the iterator to the first edge.

         /// This constructor sets the iterator to the first edge of \c g.

         /// This constructor sets the iterator to the first edge of \c g.

         UndirEdgeIt(const UndirGraph&) { }

         UndirEdgeIt(const UndirGraph&) { }

         /// UndirEdge -> UndirEdgeIt conversion

         /// UndirEdge -> UndirEdgeIt conversion

         /// Sets the iterator to the value of the trivial iterator \c e.

         /// Sets the iterator to the value of the trivial iterator \c e.

         /// This feature necessitates that each time we 

         /// This feature necessitates that each time we 

         IncEdgeIt(Invalid) { }

         IncEdgeIt(Invalid) { }

         /// This constructor sets the iterator to first incident edge.

         /// This constructor sets the iterator to first incident edge.

         /// This constructor set the iterator to the first incident edge of

         /// This constructor set the iterator to the first incident edge of

         /// the node.

         /// the node.

         IncEdgeIt(const UndirGraph&, const Node&) { }

         IncEdgeIt(const UndirGraph&, const Node&) { }

         /// UndirEdge -> IncEdgeIt conversion

         /// UndirEdge -> IncEdgeIt conversion

         /// Sets the iterator to the value of the trivial iterator \c e.

         /// Sets the iterator to the value of the trivial iterator \c e.

         /// This feature necessitates that each time we 

         /// This feature necessitates that each time we