private Multimap<String, TaggedRegion> makeTags(Collection<TaggedRegion> tags) {
   Multimap<String, TaggedRegion> ret = ArrayListMultimap.create();
   for (TaggedRegion r : tags) {
     ret.put(r.getName(), r);
   }
   return ret;
 }
 private static void saveRegion(DataKey key, TaggedRegion value) {
   saveLocation(key.getRelative("min"), value.getMin());
   saveLocation(key.getRelative("max"), value.getMax());
 }