public static function convertCommunityIdToSteamId($communityId) {
        $steamId1 = bcmod($communityId, 2);
        $steamId2 = bcsub($communityId, 76561197960265728);

        if ($steamId2 <= 0) {
            throw new SteamCondenserException("SteamID $communityId is too small.");
        }

        $steamId2 = ($steamId2 - $steamId1) / 2;

        return "STEAM_0:$steamId1:$steamId2";
    }