Reason string       // additional reason
}

func (e http2connError) Error() string {
	return fmt.Sprintf("http2: connection error: %v: %v", e.Code, e.Reason)
}

type http2pseudoHeaderError string

func (e http2pseudoHeaderError) Error() string {
	return fmt.Sprintf("invalid pseudo-header %q", string(e))
}

type http2duplicatePseudoHeaderError string