synchronized Map<Object, StubIdList> getIfRestored(StubIndexKey<?, ?> indexKey) {
      Map<StubIndexKey<?, ?>, Map<Object, StubIdList>> map = myMap;
      return map != null ? map.get(indexKey) : null;
    }
synchronized Map<Object, StubIdList> getIfRestored(StubIndexKey<?, ?> indexKey)