public function request($method, $path, $paramData)
    {
        if($method == 'get' && count($paramData) > 0) {
            $path = $path . '?' . http_build_query($paramData);
            $paramData=array();
        }
        $this->setSignature($path, $paramData);
        $req = $this->client->createRequest($method, $path, array());
        if($method == 'post' || $method == 'delete') {
            foreach ($paramData as $k => $v) {
                $req->setPostField($k, $v);
            }
        }
        try {
            $res = $req->send();
            return $res->json();
        } catch (\Guzzle\Common\Exception\RuntimeException $e) {
            echo $e->getResponse()->getBody();
        }
    }