public function getConsumedExtraTime($tags = null, $maxTime = 0, $target = TimePoint::TARGET_SERVER)
    {
        if ($maxTime) {
            $totalConsumed = $this->compute($tags, $target);
            $consumedExtraTime = $totalConsumed - $maxTime < 0 ? 0 : $totalConsumed - $maxTime;
            $this->setConsumedExtraTime($consumedExtraTime)->save();
        }
        return $this->consumedExtraTime;
    }