/**
  * Sets/updates the latest comments JSON cache file.
  *
  * @param array $data_array The data array to store in the file.
  * @return void
  * @author Paul Hughes
  * @since 3.0.2
  */
 protected static function updateJsonFile($data_array)
 {
     if (!is_array($data_array)) {
         return;
     }
     $content = json_encode(array('latest_comments_posts' => $data_array));
     // Write the file.
     Muut_Files_Utility::writeFile('cache/' . self::LATEST_COMMENTS_JSON_FILE_NAME, $content);
 }