code: public ListenableFuture<List<String>> listHosts(final Set<String> unparsedHostSelectors) {
      final Multimap<String, String> query = HashMultimap.create();
      query.putAll("selector", unparsedHostSelectors);
  
      return listHosts(query);
    }
docs: Returns a list of all hosts registered in the Helios cluster which match the given list of
  host
  selectors.
  <p>
  For example, {@code listHosts(Arrays.asList("site=foo"))} will return all agents in the
  cluster whose labels match the expression {@code site=foo}.</p>