public function getChannelSubscribers($channelIdentifier, $accessToken, $limit = 25, $offset = 0, $direction = 'desc')
    {
        if ($this->apiVersionIsGreaterThanV3() && !is_numeric($channelIdentifier)) {
            throw new InvalidIdentifierException('channel');
        }

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

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

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

        $params = [
            'limit' => intval($limit),
            'offset' => intval($offset),
            'direction' => $direction,
        ];

        return $this->get(sprintf('channels/%s/subscriptions', $channelIdentifier), $params, $accessToken);
    }