} catch (CloneNotSupportedException e) {
        // falls through
      }
    }
    return new MessageDigestHasher(getMessageDigest(prototype.getAlgorithm()), bytes);
  }

  private static final class SerializedForm implements Serializable {
    private final String algorithmName;
    private final int bytes;
    private final String toString;

      } catch (CloneNotSupportedException e) {
        // falls through
      }
    }
    return new MessageDigestHasher(getMessageDigest(prototype.getAlgorithm()), bytes);
  }

  private static final class SerializedForm implements Serializable {
    private final String algorithmName;
    private final int bytes;
    private final String toString;

      try {
        return new MacHasher((Mac) prototype.clone());
      } catch (CloneNotSupportedException e) {
        // falls through
      }
    }
    return new MacHasher(getMac(prototype.getAlgorithm(), key));
  }

  @Override
  public String toString() {
    return toString;
  }

  /** Hasher that updates a {@link Mac} (message authentication code). */