public function getRoundChangedEvent($roundId)
    {
        $this->_ensureRounds();

        if (isset($this->_rounds[$roundId]['gro_changed_event']) && $this->_rounds[$roundId]['gro_changed_event']) {
            return $this->events->loadRoundChangedEvent($this->_rounds[$roundId]['gro_changed_event']);
        }
    }