public static function selectMatchListForGame(
        $matchState,
        $gameKey
    ) {
        $matchState = (object) $matchState;
        $gameKey = (string) $gameKey;

        $matchList = [];
        foreach ($matchState->match as $matchKey => $matchItem) {
            if ($matchItem->gameKey != $gameKey) {
                continue;
            }

            $matchList[$matchKey] = $matchItem;
        }

        return $matchList;
    }