code: def checkin(self, place_id, sensor=False):
          
          data = {'placeid': place_id}
          url, checkin_response = _fetch_remote_json(
                  GooglePlaces.CHECKIN_API_URL % (str(sensor).lower(),
                          self.api_key), json.dumps(data), use_http_post=True)
          _validate_response(url, checkin_response)
docs: Checks in a user to a place.
  
          keyword arguments:
          place_id  -- The unique Google identifier for the relevant place.
          sensor    -- Boolean flag denoting if the location came from a
                       device using its location sensor (default False).