---
upgrade:
  - The ``validate_v3_token()`` and
    ``validate_non_persistent_token()`` methods have been
    removed from the token provider interface. The token
    provider API now uses a single validation method
    called ``validate_token()``. Having any validation method
    defined except ``validate_token()`` will fail since the
    interface no longer includes legacy methods. Please take
    this into consideration and plan accordingly if you're
    maintaining a custom token provider.
critical:
  - If writing a custom token provider, see the upgrade
    section about the removal of the ``validate_v3_token()``
    and ``validate_non_persistent()`` token methods.