private function getStat($stat, $soxi_arg, $cast)
    {
        if (!isset($this->$stat)) {
            $this->$stat = isset($this->stats) ?
                    (float)$this->stats->$stat :
                    (float)$this->soxi($soxi_arg);
        
            settype($this->$stat, $cast);
        }
        
        return $this->$stat;
    }