diff --git a/lemon/concepts/digraph.h b/lemon/concepts/digraph.h
--- a/lemon/concepts/digraph.h
+++ b/lemon/concepts/digraph.h
@@ -2,7 +2,7 @@
  *
  * This file is a part of LEMON, a generic C++ optimization library.
  *
- * Copyright (C) 2003-2009
+ * Copyright (C) 2003-2011
  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
  * (Egervary Research Group on Combinatorial Optimization, EGRES).
  *
@@ -435,7 +435,7 @@
 
       private:
         ///Copy constructor
-        NodeMap(const NodeMap& nm) : 
+        NodeMap(const NodeMap& nm) :
           ReferenceMap<Node, T, T&, const T&>(nm) { }
         ///Assignment operator
         template <typename CMap>