private function autoAssign($attributes = null)
  {
    if (!is_array($attributes)) return false;

    $this->max     = isset($attributes[0]) ? $attributes[0] : $this->max;
    $this->minutes = isset($attributes[1]) ? $attributes[1] : 1;
    $this->decay   = isset($attributes[1]) ? strtotime($attributes[1] . ' minutes', 0) : $this->decay;

    return true;
  }