public function getToken()
    {
        if (!$this->_restclient) {
            $this->_restclient = new RestClient();
        }
        $data = ['grant_type'    => 'client_credentials',
            'client_id'     => $this->get('CLIENT_ID'),
            'client_secret' => $this->get('CLIENT_SECRET')];
        $this->_restclient->setHttpParam('address', $this->get('base_url'));
        $response = $this->_restclient->post("/oauth/token", ['json_data' => json_encode($data)]);
        return $response['body'];
    }