Hashing.hmacSha1(keyData).toString());

    assertEquals(
        "Hashing.hmacSha256(Key[algorithm=HmacSHA256, format=RAW])",
        Hashing.hmacSha256(SHA256_KEY).toString());
    assertEquals(
        "Hashing.hmacSha256(Key[algorithm=HmacSHA256, format=RAW])",
        Hashing.hmacSha256(keyData).toString());

    assertEquals(

  /**
   * Returns a hash function implementing the Message Authentication Code (MAC) algorithm, using the
   * MD5 (128 hash bits) hash function and a {@link SecretKeySpec} created from the given byte array
   * and the MD5 algorithm.
   *
   * <p>If you are designing a new system that needs HMAC, prefer {@link #hmacSha256} or other
   * future-proof algorithms <a

        Hashing.hmacSha1(keyData).toString());

    assertEquals(
        "Hashing.hmacSha256(Key[algorithm=HmacSHA256, format=RAW])",
        Hashing.hmacSha256(SHA256_KEY).toString());
    assertEquals(
        "Hashing.hmacSha256(Key[algorithm=HmacSHA256, format=RAW])",
        Hashing.hmacSha256(keyData).toString());

    assertEquals(

  //  - Some providers may choose to also include alias names.
  //  - For example, the "SHA-1" algorithm might be referred to as "SHA1".
  //  - The algorithm name is not case-sensitive.
  private static final ImmutableMap<String, HashFunction> ALGORITHMS =
      new ImmutableMap.Builder<String, HashFunction>()
          .put("MD5", Hashing.md5())

  //  - Some providers may choose to also include alias names.
  //  - For example, the "SHA-1" algorithm might be referred to as "SHA1".
  //  - The algorithm name is not case-sensitive.
  private static final ImmutableMap<String, HashFunction> ALGORITHMS =
      new ImmutableMap.Builder<String, HashFunction>()
          .put("MD5", Hashing.md5())

  }

  /**
   * Returns a {@link Collection} of all the permutations of the specified {@link Iterable}.
   *
   * <p><i>Notes:</i> This is an implementation of the algorithm for Lexicographical Permutations
   * Generation, described in Knuth's "The Art of Computer Programming", Volume 4, Chapter 7,
   * Section 7.2.1.2. The iteration order follows the lexicographical order. This means that the

      }
    };

    abstract int resultIndex(int higherIndex);
  }

  /**
   * Searches the specified naturally ordered list for the specified object using the binary search
   * algorithm.
   *
   * <p>Equivalent to {@link #binarySearch(List, Function, Object, Comparator, KeyPresentBehavior,
   * KeyAbsentBehavior)} using {@link Ordering#natural}.
   */

      return b;
    } else if (b == 0) {
      return a; // similar logic
    }
    /*
     * Uses the binary GCD algorithm; see http://en.wikipedia.org/wiki/Binary_GCD_algorithm. This is
     * >40% faster than the Euclidean algorithm in benchmarks.
     */
    int aTwos = Integer.numberOfTrailingZeros(a);
    a >>= aTwos; // divide out all 2s
    int bTwos = Integer.numberOfTrailingZeros(b);

      return b;
    } else if (b == 0) {
      return a; // similar logic
    }
    /*
     * Uses the binary GCD algorithm; see http://en.wikipedia.org/wiki/Binary_GCD_algorithm. This is
     * >60% faster than the Euclidean algorithm in benchmarks.
     */
    int aTwos = Long.numberOfTrailingZeros(a);
    a >>= aTwos; // divide out all 2s
    int bTwos = Long.numberOfTrailingZeros(b);

  }

  /**
   * Returns a {@link Collection} of all the permutations of the specified {@link Iterable}.
   *
   * <p><i>Notes:</i> This is an implementation of the algorithm for Lexicographical Permutations
   * Generation, described in Knuth's "The Art of Computer Programming", Volume 4, Chapter 7,
   * Section 7.2.1.2. The iteration order follows the lexicographical order. This means that the