public static long hash64(byte[] data) {
    return hash64(data, 0, data.length, DEFAULT_SEED);
  }
Murmur3 64-bit variant. This is essentially MSB 8 bytes of Murmur3 128-bit variant.

@param data - input byte array
@return - hashcode
storage-api/src/java/org/apache/hive/common/util/Murmur3.java