Accessing negotiated ALPN protocol from ReactPHP Socket

[masakielastic]

Hello,

I am experimenting with minimal HTTP/2 client and server implementations
using ReactPHP Socket.

In these experiments I need to detect the negotiated ALPN protocol
(e.g. "h2") after the TLS handshake.

With plain PHP streams this can be obtained via:

stream_get_meta_data($stream)['crypto']['alpn_protocol']

However, this information is not currently accessible through the
ReactPHP Socket connection API.

For reference, I previously shared a minimal HTTP/2 example here:

https://github.com/orgs/reactphp/discussions/616

Would it make sense for ReactPHP Socket to expose the negotiated ALPN
protocol (or TLS metadata) through the connection interface?
For example:

$connection->getAlpnProtocol()

I would appreciate any feedback on whether this fits ReactPHP's
design direction.