code: public static long[] hashToLongs(final String datum, final long seed) {
      if ((datum == null) || datum.isEmpty()) {
        return null;
      }
      final byte[] data = datum.getBytes(UTF_8);
      return hash(data, seed);
    }
docs: Hash a String and long seed.
  
  @param datum the input String.
  @param seed A long valued seed.
  @return The 128-bit hash as a long[2].