def _id_to_header(self, id_):
    """Convert an id to a Content-ID header value.

    Args:
      id_: string, identifier of individual request.

    Returns:
      A Content-ID header with the id_ encoded into it. A UUID is prepended to
      the value because Content-ID headers are supposed to be universally
      unique.
    """
    if self._base_id is None:
      self._base_id = uuid.uuid4()

    return '<%s+%s>' % (self._base_id, urllib.quote(id_))
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/google-api-python-client/apiclient/http.py/BatchHttpRequest._id_to_header/original