// protocol switch response and if KeepAlives are not enabled.
	// See https://golang.org/issue/36381.
	delConnectionHeader := w.closeAfterReply &&
		(!keepAlivesEnabled || !hasToken(cw.header.get("Connection"), "close")) &&
		!isProtocolSwitchResponse(w.status, header)
	if delConnectionHeader {
		delHeader("Connection")
		if w.req.ProtoAtLeast(1, 1) {
			setHeader.connection = "close"