What sort of strange items have you seen used by gas stations to attach to the bathroom door keys, to keep people from leaving the station with the bathroom key?

I've seen lug wrenches, squeegees, cement bricks, hubcaps, and clipboards 

https://www.reddit.com/r/mildlyinteresting/comments/1f46hta/gas_station_really_doesnt_want_you_to_lose_the/?rdt=38426

https://247allentownemergencylocksmith.com/hilarious-gas-station-bathroom-keys/