private static long fmix64(long h) {
    h ^= (h >>> 33);
    h *= 0xff51afd7ed558ccdL;
    h ^= (h >>> 33);
    h *= 0xc4ceb9fe1a85ec53L;
    h ^= (h >>> 33);
    return h;
  }
Murmur3 128-bit variant.

@param data   - input byte array
@param offset - the first element of array
@param length - length of array
@param seed   - seed. (default is 0)
@return - hashcode (2 longs)
storage-api/src/java/org/apache/hive/common/util/Murmur3.java