if w.wants10KeepAlive && keepAlivesEnabled {
		sentLength := header.get("Content-Length") != ""
		if sentLength && header.get("Connection") == "keep-alive" {
			w.closeAfterReply = false
		}
	}

	// Check for an explicit (and valid) Content-Length header.
	hasCL := w.contentLength != -1

	if w.wants10KeepAlive && (isHEAD || hasCL || !bodyAllowedForStatus(w.status)) {