Fixing mouse.processEvent method

@@ -38,6 +38,8 @@ var Mouse = function(casper) {
     if (!utils.isCasperObject(casper)) {
         throw new CasperError('Mouse() needs a Casper instance');
     }
+    
+    var slice = Array.prototype.slice;
 
     var supportedEvents = ['mouseup', 'mousedown', 'click', 'mousemove'];
 
@@ -54,7 +56,7 @@ var Mouse = function(casper) {
         if (!utils.isString(type) || supportedEvents.indexOf(type) === -1) {
             throw new CasperError('Mouse.processEvent(): Unsupported mouse event type: ' + type);
         }
-        args = Array.prototype.slice.call(args); // cast Arguments -> Array
+        args = slice.call(args); // cast Arguments -> Array
         casper.emit('mouse.' + type.replace('mouse', ''), args);
         switch (args.length) {
             case 0:
@@ -79,7 +81,9 @@ var Mouse = function(casper) {
         }
     }
     
-    this.processEvent = processEvent;
+    this.processEvent = function() {
+        processEvent(arguments[0], slice.call(arguments, 1));
+    }
 
     this.click = function click() {
         processEvent('click', arguments);