OAuthAccessToken describes an OAuth access token. The name of a token must be prefixed with a sha256~
string, must not contain "/" or "%" characters and must be at least 32 characters long.
The name of the token is constructed from the actual token by sha256-hashing it and using URL-safe unpadded base64-encoding (as described in RFC4648) on the hashed result.
Compatibility level 1: Stable within a major release for a minimum of 12 months or 3 minor releases (whichever is longer).