// when the stream's ReadTimeout has fired.
func (st *http2stream) onReadTimeout() {
	if st.body != nil {
		// Wrap the ErrDeadlineExceeded to avoid callers depending on us
		// returning the bare error.
		st.body.CloseWithError(fmt.Errorf("%w", os.ErrDeadlineExceeded))
	}
}

// onWriteTimeout is run on its own goroutine (from time.AfterFunc)
// when the stream's WriteTimeout has fired.