private static final Logger LOG = LoggerFactory.getLogger(ForkedZooKeeperInspector.class);
public List<List<String>> extractShardUrls(String zkHost, String collection) {
DocCollection docCollection = extractDocCollection(zkHost, collection);
List<Slice> slices = getSortedSlices(docCollection.getSlices());
List<List<String>> solrUrls = new ArrayList<List<String>>(slices.size());
for (Slice slice : slices) {
if (slice.getLeader() == null) {
throw new IllegalArgumentException("Cannot find SolrCloud slice leader. " +
"It looks like not all of your shards are registered in ZooKeeper yet");