how can i expand to menu item?

below code is example of CCMenu but i can't find to expand to each one of menu item size

```
// Create some menu items
CCMenuItemImage * menuItem1 = [CCMenuItemImage itemFromNormalImage:@"myfirstbutton.png"
selectedImage: @"myfirstbutton_selected.png"
target:self
selector:@selector(doSomethingOne:)];

CCMenuItemImage * menuItem2 = [CCMenuItemImage itemFromNormalImage:@"mysecondbutton.png"
selectedImage: @"mysecondbutton_selected.png"
target:self
selector:@selector(doSomethingTwo:)];

CCMenuItemImage * menuItem3 = [CCMenuItemImage itemFromNormalImage:@"mythirdbutton.png"
selectedImage: @"mythirdbutton_selected.png"
target:self
selector:@selector(doSomethingThree:)];

// Create a menu and add your menu items to it
CCMenu * myMenu = [CCMenu menuWithItems:menuItem1, menuItem2, menuItem3, nil];

// Arrange the menu items vertically
[myMenu alignItemsVertically];

```