code: func StronglyConnected(g *Graph) [][]Vertex {
  	vs := g.Vertices()
  	acct := sccAcct{
  		NextIndex:   1,
  		VertexIndex: make(map[Vertex]int, len(vs)),
  	}
  	for _, v := range vs {
  		// Recurse on any non-visited nodes
  		if acct.VertexIndex[v] == 0 {
  			stronglyConnected(&acct, g, v)
  		}
  	}
  	return acct.SCC
  }
docs: // StronglyConnected returns the list of strongly connected components
  // within the Graph g. This information is primarily used by this package
  // for cycle detection, but strongly connected components have widespread
  // use.