byte[] original = hash.asBytes();
    byte[] mutated = hash.asBytes();
    mutated[0]++;
    assertThat(hash.asBytes()).isEqualTo(original);
  }

  private static void assertReadableBytes(HashCode hashCode) {
    assertThat(hashCode.bits()).isAtLeast(32); // sanity
    byte[] hashBytes = hashCode.asBytes();
    int totalBytes = hashCode.bits() / 8;

  public void testParanoidHashBytes() {
    HashFn hf =
        new HashFn() {
          @Override
          public byte[] hash(byte[] input, int seed) {
            return murmur3_32(seed).hashBytes(input).asBytes();
          }
        };
    // Murmur3A, MurmurHash3 for x86, 32-bit (MurmurHash3_x86_32)
    // https://github.com/aappleby/smhasher/blob/master/src/main.cpp
    HashTestUtils.verifyHashFunction(hf, 32, 0xB0F57EE3);

    byte[] original = hash.asBytes();
    byte[] mutated = hash.asBytes();
    mutated[0]++;
    assertThat(hash.asBytes()).isEqualTo(original);
  }

  private static void assertReadableBytes(HashCode hashCode) {
    assertThat(hashCode.bits()).isAtLeast(32); // sanity
    byte[] hashBytes = hashCode.asBytes();
    int totalBytes = hashCode.bits() / 8;

  public void testParanoidHashBytes() {
    HashFn hf =
        new HashFn() {
          @Override
          public byte[] hash(byte[] input, int seed) {
            return murmur3_32(seed).hashBytes(input).asBytes();
          }
        };
    // Murmur3A, MurmurHash3 for x86, 32-bit (MurmurHash3_x86_32)
    // https://github.com/aappleby/smhasher/blob/master/src/main.cpp
    HashTestUtils.verifyHashFunction(hf, 32, 0xB0F57EE3);

          @Override
          public byte[] hash(byte[] input, int seed) {
            Hasher hasher = murmur3_128(seed).newHasher();
            byteArrayFunnel().funnel(input, hasher);
            return hasher.hash().asBytes();
          }
        };
    // Murmur3F, MurmurHash3 for x64, 128-bit (MurmurHash3_x64_128)
    // From http://code.google.com/p/smhasher/source/browse/trunk/main.cpp

  }

  public void testConcatenatingHashFunction_makeHash() {
    byte[] md5Hash = Hashing.md5().hashLong(42L).asBytes();
    byte[] murmur3Hash = Hashing.murmur3_32().hashLong(42L).asBytes();
    byte[] combined = new byte[md5Hash.length + murmur3Hash.length];
    ByteBuffer buffer = ByteBuffer.wrap(combined);
    buffer.put(md5Hash);
    buffer.put(murmur3Hash);