+ * Send an xmlrpc request to the server.
+ *
+ * @param Request|Request[]|string $req The Request object, or an array of requests for using multicall, or the
+ * complete xml representation of a request.
+ * When sending an array of Request objects, the client will try to make use of
+ * a single 'system.multicall' xml-rpc method call to forward to the server all
+ * the requests in a single HTTP round trip, unless $this->no_multicall has
+ * been previously set to TRUE (see the multicall method below), in which case
+ * many consecutive xmlrpc requests will be sent. The method will return an
+ * array of Response objects in both cases.
+ * The third variant allows to build by hand (or any other means) a complete
+ * xmlrpc request message, and send it to the server. $req should be a string
+ * containing the complete xml representation of the request. It is e.g. useful
+ * when, for maximal speed of execution, the request is serialized into a
+ * string using the native php xmlrpc functions (see http://www.php.net/xmlrpc)
+ * @param integer $timeout Connection timeout, in seconds, If unspecified, a platform specific timeout will apply.
+ * This timeout value is passed to fsockopen(). It is also used for detecting server
+ * timeouts during communication (i.e. if the server does not send anything to the client
+ * for $timeout seconds, the connection will be closed).
+ * @param string $method valid values are 'http', 'http11' and 'https'. If left unspecified, the http protocol
+ * chosen during creation of the object will be used.