public boolean connect(VertexInterface<T> endVertex, double edgeWeight)
{
   boolean result = false;

   if (!this.equals(endVertex))
   {  // Vertices are distinct
      Iterator<VertexInterface<T>> neighbors = getNeighborIterator();
      boolean duplicateEdge = false;

      while (!duplicateEdge && neighbors.hasNext())
      {
         VertexInterface<T> nextNeighbor = neighbors.next();
         if (endVertex.equals(nextNeighbor))
            duplicateEdge = true;
      } // end while

      if (!duplicateEdge)
      {
         edgeList.add(new Edge(endVertex, edgeWeight));
         result = true;
      } // end if
   } // end if

   return result;
} // end connect

public boolean connect(VertexInterface<T> endVertex)
{
   return connect(endVertex, 0);
} // end connect
// Version 4.0