public function connectToPreview(\Step\Api\TokenUser $I)
 {
     $I->am('a guest with a token');
     $I->wantTo('make sure I can get the preview');
     $data = $I->getFilesDataForFolder('shared1');
     $file = $data['testimage.gif'];
     $url = GalleryApp::$URL . '/preview.public/' . $file['id'];
     $params = ['width' => 800, 'height' => 600];
     $this->connect($I, $url, $params, $this->browserHeader);
     $I->downloadAFile($file, 'testimage.gif');
 }