}
  }

  @Override
  public Hasher newHasher() {
    if (supportsClone) {
      try {
        return new MessageDigestHasher((MessageDigest) prototype.clone(), bytes);
      } catch (CloneNotSupportedException e) {
        // falls through
      }
    }
    return new MessageDigestHasher(getMessageDigest(prototype.getAlgorithm()), bytes);
  }

  private static final class SerializedForm implements Serializable {