docs: public static <K, V, NK, NV> Map<NK, NV> newChangedKeyValueMap(
              Map<K, V> map, Function<K, NK> changingKeyFunction,
              Function<V, NV> changingValueFunction) {
          return buildEntryStream(map).collect(toMap(
                  entry -> changingKeyFunction.apply(entry.getKey()),
                  entry -> changingValueFunction.apply(entry.getValue())));
      }