class ExtraFieldPropagation implements Propagation<K> {

  @Deprecated public static Factory newFactory(Propagation.Factory delegate, String... names) {
    if (delegate == null) throw new NullPointerException("delegate == null");
    if (names == null) throw new NullPointerException("names == null");
    return newFactory(delegate, Arrays.asList(names));
  }

    ExtraFieldPropagation(Propagation<K> delegate, List<K> extraKeys);

}