[Boost-users] [BGL] creating a single vertex for the loop in a graph

Hello All, I am looking for the following in boost graph. I have a graph in which I am able to find out the loops. Now, I wanted to replace the whole loop with a single vertex in the same Graph. Is that possible ? if it is, can you suggest me how do it. Alternate way could be, I copy the loop and make another graph and add this whole graph as a "vertex" in initial graph. Can I add a "graph" as a vertex to existing graph? Thanks and regards, Srinivas Boppu