public bool removeVertex(TV v)
 {
     if (containsVertex(v))
     {
         ICollection <TE> edges = edgesOf(v);
         foreach (TE e in edges)
         {
             removeEdgeFromContainer(e);
         }
         return(delegator.removeVertex(v));
     }
     else
     {
         return(false);
     }
 }