class VertexLink
   {
   public Vertex vData;              	// data item (key)
   public VertexLink next;              // next link in list
// -------------------------------------------------------------
   public VertexLink(Vertex id, VertexLink newNext) // constructor
      {
      vData = id;
      next = newNext;
      }
// -------------------------------------------------------------
   public void displayLink()      // display ourself
      {
      System.out.print("{" + sData + "} ");
      }
   }  // end class Link