Currently the parameters of [`hyper::Service::call`](https://docs.rs/hyper/0.14.4/hyper/service/trait.Service.html#tymethod.call) only include a [`Request`](https://docs.rs/hyper/0.14.4/hyper/struct.Request.html). And I'm curious if it's possible to access [`rustls::Session`](https://docs.rs/rustls/0.19.0/rustls/trait.Session.html) somewhere from the [`Service`](https://docs.rs/hyper/0.14.4/hyper/service/trait.Service). Accessing TLS session could be useful for multiple reasons, for example for implementing applications that rely on the [TLS Keying Material](https://tools.ietf.org/html/rfc5705) (provided by [`rustls::Session::export_keying_material`](https://docs.rs/rustls/0.19.0/rustls/trait.Session.html#tymethod.export_keying_material)). cc @tiziano88