public static List toEdges(Collection dirEdges){
  List edges=new ArrayList();
  for (Iterator i=dirEdges.iterator(); i.hasNext(); ) {
    edges.add(((DirectedEdge)i.next()).parentEdge);
  }
  return edges;
}

public static List toEdges ( Collection dirEdges ) { List edges = new ArrayList ( ) ; for ( Iterator i = dirEdges . iterator ( ) ; i . hasNext ( ) ; ) { edges . add ( ( ( DirectedEdge ) i . next ( ) ) . parentEdge ) ; } return edges ; }
returns a list containing the parent edge ( possibly null ) for each of the given directededges .
