/*
- * Copyright (C) 2016-2019 "IoT.bzh"
+ * Copyright (C) 2015-2020 "IoT.bzh"
* Author: José Bollo <jose.bollo@iot.bzh>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* Establishes for the client link identified by 'req' a subscription
* to the 'event'.
*
+ * Establishing subscription MUST be called BEFORE replying to the request.
+ *
* @param req the request
* @param event the event to subscribe
*
* link identified by 'req'.
* Returns 0 in case of successful subscription or -1 in case of error.
*
+ * Revoking subscription MUST be called BEFORE replying to the request.
+ *
* @param req the request
* @param event the event to revoke
*