/**
  * Returns entry content; or NULL for directories
  *
  * @param   io.archive.zip.ZipEntry $entry
  * @return  string
  */
 protected function entryContent(ZipEntry $entry)
 {
     if ($entry->isDirectory()) {
         return null;
     } else {
         return (string) Streams::readAll($entry->in());
     }
 }