+ * string describing the type of success of the request.
+ *
+ * (Object|String) data - Data to be sent to the server. Converted to a query
+ * string, if not already a string. Is appended to the url for GET-requests.
+ * See processData option to prevent this automatic processing.
+ *
+ * (String) contentType - When sending data to the server, use this content-type.
+ * Default is "application/x-www-form-urlencoded", which is fine for most cases.
+ *
+ * (Boolean) processData - By default, data passed in to the data option as an object
+ * other as string will be processed and transformed into a query string, fitting to
+ * the default content-type "application/x-www-form-urlencoded". If you want to send
+ * DOMDocuments, set this option to false.
+ *
+ * (Boolean) async - By default, all requests are sent asynchronous (set to true).
+ * If you need synchronous requests, set this option to false.
+ *
+ * (Function) beforeSend - A pre-callback to set custom headers etc., the
+ * XMLHttpRequest is passed as the only argument.