code: public Reflections merge(final Reflections reflections) {
          if (reflections.store != null) {
              for (String indexName : reflections.store.keySet()) {
                  Multimap<String, String> index = reflections.store.get(indexName);
                  for (String key : index.keySet()) {
                      for (String string : index.get(key)) {
                          store.getOrCreate(indexName).put(key, string);
                      }
                  }
              }
          }
          return this;
      }
docs: merges a Reflections instance metadata into this instance