Refactor fetch.

Author: killme2008

lib/object.js

@@ -769,30 +769,26 @@
      * Fetch the model from the server. If the server's representation of the
      * model differs from its current attributes, they will be overriden,
      * triggering a <code>"change"</code> event.
+     * @param {Object} fetchOptions Optional options to set 'keys' and
+     *      'include' option.
      * @param {Object} options Optional Backbone-like options object to be
-     *     passed in to set. Also you can set 'keys' and 'include' options.
+     *     passed in to set.
      * @return {AV.Promise} A promise that is fulfilled when the fetch
      *     completes.
      */
-    fetch: function(options) {
-      var include = null;
-      var keys = null;
-      if(options) {
-        var processOpt = function(k) {
-          if(options[k]){
-            if(_.isArray(options[k])) {
-              return options[k].join(',');
-            } else {
-              return options[k];
-            }
-          }
-        };
-        include = processOpt('include');
-        keys = processOpt('keys');
+    fetch: function() {
+      var options = null;
+      var fetchOptions = {};
+      if(arguments.length == 1) {
+        options = arguments[0];
+      } else if(arguments.length == 2) {
+        fetchOptions = arguments[0];
+        options = arguments[1];
       }
+
       var self = this;
       var request = AV._request("classes", this.className, this.id, 'GET',
-                                { include: include, keys: keys});
+                                fetchOptions);
       return request.then(function(response, status, xhr) {
         self._finishFetch(self.parse(response, status, xhr), true);
         return self;