/**
  * expand super types after scanning, for super types that were not scanned. this is helpful in
  * finding the transitive closure without scanning all 3rd party dependencies. it uses {@link
  * ReflectionUtils#getSuperTypes(Class)}.
  *
  * <p>for example, for classes A,B,C where A supertype of B, B supertype of C:
  *
  * <ul>
  *   <li>if scanning C resulted in B (B->C in store), but A was not scanned (although A supertype
  *       of B) - then getSubTypes(A) will not return C
  *   <li>if expanding supertypes, B will be expanded with A (A->B in store) - then getSubTypes(A)
  *       will return C
  * </ul>
  */
 public void expandSuperTypes() {
   if (store.keySet().contains(index(SubTypesScanner.class))) {
     Multimap<String, String> mmap = store.get(index(SubTypesScanner.class));
     Sets.SetView<String> keys = Sets.difference(mmap.keySet(), Sets.newHashSet(mmap.values()));
     Multimap<String, String> expand = HashMultimap.create();
     for (String key : keys) {
       expandSupertypes(expand, key, forName(key));
     }
     mmap.putAll(expand);
   }
 }
 /** merges a Reflections instance metadata into this instance */
 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;
 }
 private void expandSupertypes(Multimap<String, String> mmap, String key, Class<?> type) {
   for (Class<?> supertype : ReflectionUtils.getSuperTypes(type)) {
     if (mmap.put(supertype.getName(), key)) {
       if (log != null) log.debug("expanded subtype {} -> {}", supertype.getName(), key);
       expandSupertypes(mmap, supertype.getName(), supertype);
     }
   }
 }