checkHmac(expected, Hashing.hmacMd5(key), data);
  }

  private static void checkHmac(String expected, HashFunction hashFunc, byte[] data) {
    assertEquals(HashCode.fromString(expected), hashFunc.hashBytes(data));
  }

  private static byte[] fillByteArray(int size, int toFillWith) {
    byte[] array = new byte[size];
    Arrays.fill(array, (byte) toFillWith);
    return array;
  }

    checkHmac(expected, Hashing.hmacMd5(key), data);
  }

  private static void checkHmac(String expected, HashFunction hashFunc, byte[] data) {
    assertEquals(HashCode.fromString(expected), hashFunc.hashBytes(data));
  }

  private static byte[] fillByteArray(int size, int toFillWith) {
    byte[] array = new byte[size];
    Arrays.fill(array, (byte) toFillWith);
    return array;
  }