public function mute($channelId, $direction)
    {
        $uri = "channels/$channelId/mute";
        try {
            $this->client->getEndpoint()->post($uri, [
                'form_params' => [
                    'direction' => $direction,
                ]
            ]);
        } catch (RequestException $e) {
            $this->processRequestException($e);
        }
    }