/**
  * Prepare fixture data for verify
  *
  * @param DownloadableProduct $product
  * @return array
  */
 protected function prepareFixtureData(DownloadableProduct $product)
 {
     $data = $this->sortDataByPath($product->getDownloadableSample(), 'downloadable/sample::sort_order');
     foreach ($data['downloadable']['sample'] as $key => $link) {
         $link = array_intersect_key($link, array_flip($this->linkField));
         $data['downloadable']['sample'][$key] = $link;
     }
     $data = array_intersect_key($data, array_flip($this->downloadableSampleField));
     return $data;
 }