public function getUsersFollowedChannels($userIdentifier, $limit = 25, $offset = 0, $direction = 'desc', $sortby = 'created_at')
    {
        $availableSortBys = ['created_at', 'last_broadcast', 'login'];

        if ($this->apiVersionIsGreaterThanV3() && !is_numeric($userIdentifier)) {
            throw new InvalidIdentifierException('user');
        }

        if (!$this->isValidLimit($limit)) {
            throw new InvalidLimitException();
        }

        if (!$this->isValidOffset($offset)) {
            throw new InvalidOffsetException();
        }

        if (!$this->isValidDirection($direction)) {
            throw new InvalidDirectionException();
        }

        if (!in_array($sortby = strtolower($sortby), $availableSortBys)) {
            throw new UnsupportedOptionException('sortby', $availableSortBys);
        }

        return $this->get(sprintf('users/%s/follows/channels', $userIdentifier), [
            'limit' => intval($limit),
            'offset' => intval($offset),
            'direction' => $direction,
            'sortby' => $sortby,
        ]);
    }