def get_dir_from_zipfile(zip_file, fallback=None):
    """Return the name of the root folder in a zip file.

    :param zip_file: a :class:`zipfile.ZipFile` instance.
    :param fallback: if `None`, the name of the zip file is used. This is
        returned if the zip file contains more than one top-level directory,
        or none at all.
    """
    fallback = fallback or zip_file.filename
    directories = [name for name in zip_file.namelist() if name.endswith("/")
                   and len(PurePath(name).parts) == 1]
    return fallback if len(directories) > 1 else directories[0]
def GetLogs(region, stream_name, group_name, token=None):
  """Fetches the JSON formatted log stream starting at the token."""
  get_cmd = util.AWS_PREFIX + [
      '--region', region,
      'logs', 'get-log-events',
      '--start-from-head',
      '--log-group-name', group_name,
      '--log-stream-name', stream_name,
  ]
  if token:
    get_cmd.extend(['--next-token', token])
  stdout, _, _ = vm_util.IssueCommand(get_cmd)
  return json.loads(stdout)