Consider to public `azure_identity`'s `TokenCache`

[magodo]

Feature Summary

Consider to public azure_identity's TokenCache

Feature Description

The TokenCache is helpful for 3rd party users who want to implement their own Credential. E.g. the cache package in Go SDK is public: https://github.com/Azure/azure-sdk-for-go/tree/main/sdk/azidentity/cache.

Use Case

No response

Alternatives

No response

Additional Context

No response

[chlowell]

These are different features. The azidentity/cache module implements persistent i.e. on-disk token caching. We're tracking that feature for azure_identity with #2636. The TokenCache azure_identity has today is an in-memory cache. It isn't stable and we want to keep it private so we can make incompatible changes to it as the crate evolves without breaking applications. Fortunately it isn't much code--I suggest simply copying it if it's useful to you in its present form.