PhpSlackBot\Bot::init PHP Method

    private function init()
    {
        $url = 'https://slack.com/api/rtm.start';
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $url . '?' . http_build_query($this->params));
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        $body = curl_exec($ch);
        if ($body === false) {
            throw new \Exception('Error when requesting ' . $url . ' ' . curl_error($ch));
        }
        curl_close($ch);
        $response = json_decode($body, true);
        if (is_null($response)) {
            throw new \Exception('Error when decoding body (' . $body . ').');
        }
        $this->context = $response;
        if (isset($response['error'])) {
            throw new \Exception($response['error']);
        }
        $this->wsUrl = $response['url'];
    }