public function getRounds()
    {
        $this->_ensureRounds();

        foreach ($this->_rounds as $roundId => $roundData) {
            if (! isset($this->_roundObjects[$roundId])) {
                $this->_roundObjects[$roundId] = $this->tracker->createTrackClass('Round', $roundData);
            }
        }
        return $this->_roundObjects;
    }