if (!neighborsForVertex.containsKey(vertex)) {
continue;
}
Subgraph subgraph = computeConnectedSubgraph(neighborsForVertex, vertex);
if (subgraph != null){
for (Iterator<Vertex> vIter = subgraph.streetIterator(); vIter.hasNext();) {
Vertex subnode = vIter.next();
subgraphs.put(subnode, subgraph);
}
islands.add(subgraph);
}