code: public static final int mixMagic(int magic1, int magic2) {
      final long prime = 2654435761L;
      long result = 1;
      result = prime * result + magic1;
      result = prime * result + magic2;
      return (int) result;
    }
docs: Mix two magic numbers into one, to obtain a combined magic. Note:
  mixMagic(a,b) != mixMagic(b,a) usually.
  
  @param magic1 Magic number to mix.
  @param magic2 Magic number to mix.
  @return Mixed magic number.