Using ClientWithMiddleware trait issue

[davidcorrigan714]

I'm trying to provide a reqwest client wrapped in caching middleware to handle caching of the open id config data and keys but hitting an issue with traits:

I've got something like:

        let client = {
            let builder = reqwest::Client::builder();
            let builder = builder.redirect(reqwest::redirect::Policy::none());
            builder
                .build()
                .with_context(|| "Building reqwest client for OIDC client.".to_owned())?
        };

        let middleware_client = ClientBuilder::new(client)
            .with(Cache(HttpCache {
                mode: CacheMode::Default,
                manager: MokaManager::default(),
                options: HttpCacheOptions::default(),
            }))
            .build();
...
        // Use OpenID Connect Discovery to fetch the provider metadata.
        let provider_metadata = CoreProviderMetadata::discover_async(
            IssuerUrl::new("https://accounts.example.com".to_string())?,
            &middleware_client,
        )
        .await?;

But the compiler is unhappy:

error[E0277]: expected a `Fn(http::Request<Vec<u8>>)` closure, found `ClientWithMiddleware`
   --> project\src\oidc.rs:77:10
    |
77  |         .await?;
    |          ^^^^^ expected an `Fn(http::Request<Vec<u8>>)` closure, found `ClientWithMiddleware`
    |
    = help: the trait `Fn(http::Request<Vec<u8>>)` is not implemented for `ClientWithMiddleware`, which is required by `ClientWithMiddleware: AsyncHttpClient<'_>`
    = help: the trait `AsyncHttpClient<'c>` is implemented for `reqwest::Client`
    = note: required for `ClientWithMiddleware` to implement `AsyncHttpClient<'_>`
note: required by a bound in `ProviderMetadata::<A, AD, CA, CN, CT, G, JE, JK, K, RM, RT, S>::discover_async`
   --> C:\Users\dcorriga\.cargo\registry\src\index.crates.io-6f17d22bba15001f\openidconnect-4.0.0\src\discovery\mod.rs:314:12

Seems like the easiest fix would be to add an implementation for AsyncHttpClient to the ClientWithMiddleware which would seem to support the intentions mentioned in this issue.. I don't think I can pull the inner client out of the middleware and still have the caching if it's doable at all.