code: public static long[] hash(final long in, final long seed, final long[] hashOut) {
      final long h1 = seed ^ mixK1(in);
      final long h2 = seed;
      return finalMix128(h1, h2, 8, hashOut);
    }
docs: Returns a 128-bit hash of the input.
  Note the entropy of the resulting hash cannot be more than 64 bits.
  @param in a long
  @param seed A long valued seed.
  @param hashOut A long array of size 2
  @return the hash