public static TimeoutBudget getTimeoutBudget(HttpRequest request, Duration defaultTimeout) {
        return getTimeoutBudget(getRequestTimeout(request, defaultTimeout));
    }
Gets session id (as a number) from request (v2). Input request must have a valid path.

@param request a request
@return a session id
configserver/src/main/java/com/yahoo/vespa/config/server/http/SessionHandler.java