private static Set<String> getUniquePathsToRegister(Collection<? extends WorkUnitState> states) {
   Set<String> paths = Sets.newHashSet();
   for (State state : states) {
     if (state.contains(ConfigurationKeys.PUBLISHER_DIRS)) {
       paths.addAll(state.getPropAsList(ConfigurationKeys.PUBLISHER_DIRS));
     }
   }
   return paths;
 }