https://github.com/encode/httpx/blob/50d337e807839c21e796fd8b01c67d8a672a9721/httpx/_dispatch/http2.py#L147-L155

IIRC, RFC defines 2 messages that may carry error_code:

• RST_STREAM - forcibly close 1 stream
• GOAWAY - close entire connection (gracefully or forcibly)

In addition, h2 might generate ResetStream event internally:

when the remote party has made a protocol error which only affects a single stream

I find it weird that there's only this one place where error_code is evaluated in the library 🤔