code: def _unpack(self):
          
          if self._ext == 'zip':
              with ZipFile(self._local, 'r') as archive:
                  archive.extractall(self._root)
          else:
              cmd = 'gunzip | tar xC ' + self._root
              proc = subprocess.Popen(cmd, shell=True, stdin=subprocess.PIPE)
              proc.stdin.write(self._local.read())
          self._local.close()
docs: Unpacks the CSPICE package on the given root directory. Note that
          Package could either be the zipfile.ZipFile class for Windows platforms
          or tarfile.TarFile for other platforms.