public function push($user)
    {
        if (! isset($this->data['message'])) {
            throw new Exception('You must supply a message');
        }

        // Fields to send
        $data = array_merge(
            $this->data,
            array(
                'user' => $user,
            )
        );

        // Send data to API
        $curl = curl_init();
        curl_setopt($curl, CURLOPT_URL, $this->api_url);
        curl_setopt($curl, CURLOPT_POST, true);
        curl_setopt($curl, CURLOPT_POSTFIELDS, $data);
        curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
        $result = json_decode(curl_exec($curl), true);
        curl_close($curl);

        return isset($result['status']) && (int) $result['status'] === 1;
    }