Laws for text map type classes?

[rossabaker]

Getter: keys-get consistency: forAll { (carrier) => keys(carrier).forall(key => get(carrier, key).isDefined)?

Updater: idempotence?: forAll { (carrier, k, v) => updated(carrier, k, v) === updated(updated(carrier, k, v), k, v)

[AprilAtBanno]

at least currently, updater idempotence isn't true for Seq carriers