code: public static long[] hashToLongs(final double datum, final long seed) {
      final double d = (datum == 0.0) ? 0.0 : datum; //canonicalize -0.0, 0.0
      final long[] data = { Double.doubleToLongBits(d) };//canonicalize all NaN forms
      return hash(data, seed);
    }
docs: Hash a double and long seed.
  
  @param datum the input double.
  @param seed A long valued seed.
  @return The 128-bit hash as a long[2].