code: public static <K, V, NK> Map<NK, V> newChangedKeyWithEntryMap(
              Map<K, V> map,
              Function<Entry<K, V>, NK> changingKeyFunction) {
          return buildEntryStream(map).collect(
                  toMap(changingKeyFunction, Entry::getValue));
      }
docs: New changed key with entry map map.
  
  @param <K>                 the type parameter
  @param <V>                 the type parameter
  @param <NK>                the type parameter
  @param map                 the map
  @param changingKeyFunction the changing key function
  @return the map