pyca/cryptography — pull request #95 by mwielgoszewski (2013-10-06 21:36:48+00:00)
Title: Make key_sizes a frozenset, since these are/should be immutable

The `key_sizes` attribute on `AES` should be an immutable type. This pull request changes the `key_sizes` type from `set` to `frozenset`.

All tests pass.