* Creates a client object for given protocol. This method uses the
* registry pattern to cache those instances.
*
- * @param $protocolInstance An instance of a ProtocolHandler class to create a client object for (e.g. 'http' for a HTTP/1.1 client)
+ * @param $protocolInstance An instance of a HandleableProtocol class to create a client object for (e.g. 'http' for a HTTP/1.1 client)
* @param $socketResource A valid socket resource (optional)
* @return $clientInstance An instance of the requested client
*/