private function plainBonus($bonus)
    {
        /* prepare data for updates */
        $result = [];
        /** @var DEntry $item */
        foreach ($bonus as $item) {
            $bonusData = $item->getEntries();
            /** @var DBonus $entry */
            foreach ($bonusData as $entry) {
                $bonus = $entry->getValue();
                if ($bonus > Cfg::DEF_ZERO) {
                    $result[] = $entry;
                }
            }
        }
        return $result;
    }