diff -r fd82adfbe905 -r 22099ef840d7 lemon/bits/clearable_graph_extender.h
--- a/lemon/bits/clearable_graph_extender.h	Mon Nov 21 12:07:05 2005 +0000
+++ b/lemon/bits/clearable_graph_extender.h	Mon Nov 21 17:48:00 2005 +0000
@@ -44,6 +44,31 @@
 
   };
 
+
+  template <typename _Base>
+  class ClearableUndirBipartiteGraphExtender : public _Base {
+  public:
+
+    typedef _Base Parent;
+    typedef ClearableUndirBipartiteGraphExtender Graph;
+
+    typedef typename Parent::Node Node;
+    typedef typename Parent::LowerNode LowerNode;
+    typedef typename Parent::UpperNode UpperNode;
+    typedef typename Parent::Edge Edge;
+    typedef typename Parent::UndirEdge UndirEdge;
+
+    void clear() {
+      Parent::getNotifier(Edge()).clear();
+      Parent::getNotifier(UndirEdge()).clear();
+      Parent::getNotifier(Node()).clear();
+      Parent::getNotifier(LowerNode()).clear();
+      Parent::getNotifier(UpperNode()).clear();
+      Parent::clear();
+    }
+
+  };
+
 }
 
 #endif