public function getRand($min = 0, $max = 0x7fffffff)
    {
        $t = ($this->x ^ ($this->x << 11)) & 0x7fffffff;
        $this->x = $this->y;
        $this->y = $this->z;
        $this->z = $this->w;
        $this->w = ( $this->w ^ ($this->w >> 19) ^ ( $t ^ ( $t >> 8 )) );
        return $this->w % ($max - $min + 1) + $min;
    }