return uintptr(rv.Uint())
	}
	return 0
}

// isClosedConnError reports whether err is an error from use of a closed
// network connection.
func http2isClosedConnError(err error) bool {
	if err == nil {
		return false
	}

	if errors.Is(err, net.ErrClosed) {
		return true
	}

	// TODO(bradfitz): x/tools/cmd/bundle doesn't really support