function _oauth_get_token()
 {
     $connection = new ASG_500px_OAuth($_REQUEST['consumer_key'], $_REQUEST['consumer_secret']);
     /* Get temporary credentials. */
     $request_token = $connection->getRequestToken(admin_url('admin.php?page=asg-500px-auth-success'));
     if (!isset($request_token['oauth_token']) || !isset($request_token['oauth_token_secret'])) {
     } else {
         session_start();
         $_SESSION['asg_500px_data'] = stripslashes_deep($_REQUEST);
         $_SESSION['asg_500px_oauth_token'] = $token = $request_token['oauth_token'];
         $_SESSION['asg_500px_oauth_token_secret'] = $request_token['oauth_token_secret'];
         wp_redirect($connection->getAuthorizeURL($token));
         exit;
     }
     exit;
 }
 function ping_token()
 {
     $oauth = new ASG_500px_OAuth($this->source['consumer_key'], $this->source['consumer_secret'], $this->source['access_token'], $this->source['access_token_secret']);
     $data = $oauth->get('https://api.500px.com/v1/collections');
     return $data !== null;
 }