default HttpRequest.Builder authenticated(HttpRequest.Builder request) {
        Map<String, String> authorizationHeaders = authorizationHeaders();
        if (authorizationHeaders.isEmpty())
            return request;

        Map<String, List<String>> headers = request.build().headers().map();
        authorizationHeaders.forEach((name, value) -> {
            if ( ! headers.containsKey(name))
                request.setHeader(name, value);
        });
        return request;
    }
Adds necessary authentication data to the given HTTP request builder, to pass the data plane of a Vespa endpoint.
tenant-cd-api/src/main/java/ai/vespa/hosted/cd/EndpointAuthenticator.java