code: public SCComponent<Vertex> getScc(Vertex v) {
  	// We don't want to allocate a full LinkedHashMap for each
  	// TopSortedCompDiGraph - too memory expensive.
  	for(SCComponent<Vertex> scc : this.incrOrder()) {
  	    if(scc.contains(v)) return scc;
  	}
  	return null;
      }
docs: @return Strongly-connected component that <code>v</code>
  belongs to; returns <code>null</code> iff <code>v</code> does
  not appear in the original dag.
  
  <p> For space-savings purposes, we do NOT construct a map from
  vertices to SCCs; instead, each <code>getScc</code> query
  takes time linear in the number of SCCs.  If you do many calls
  to this method, you may want to use {@link
  #getVertex2SccMap()}.