public static EdgeDoubleDictionary UnaryWeightsFromEdgeList(IEdgeListGraph graph)
 {
     if (graph == null)
     {
         throw new ArgumentNullException("graph");
     }
     EdgeDoubleDictionary dictionary = new EdgeDoubleDictionary();
     IEdgeEnumerator enumerator = graph.get_Edges().GetEnumerator();
     while (enumerator.MoveNext())
     {
         IEdge edge = enumerator.get_Current();
         dictionary.set_Item(edge, 1.0);
     }
     return dictionary;
 }