EtherpadLite\Client::getRevisionChangeset PHP Method

    public function getRevisionChangeset($padID, $rev = null)
    {
        $params = array();
        $params['padID'] = $padID;
        if (isset($rev)) {
            $params['rev'] = $rev;
        }
        return $this->get("getRevisionChangeset", $params);
    }