public function generateNextRoundsFights()
    {
        $fightersCount = $this->championship->competitors->count() + $this->championship->teams->count();
        $maxRounds = $this->getNumRounds($fightersCount);
        for ($numRound = 1; $numRound < $maxRounds; $numRound++) {
            $groupsByRound = $this->championship->fightersGroups()->where('round', $numRound)->with('parent', 'children')->get();
            $this->updateParentFight($groupsByRound); // should be groupsByRound
        }
    }