I want to pass an NSInteger argument to a method called using performSelector:WithObject:afterDelay, so I have this code:

```
   id arg = [NSNumber numberWithInt:myIdentifier]; 
   [self performSelector:@selector(myMethod:) withObject:arg afterDelay:kDuration];

    - (void) myMethod: (id) identifier
    {
    ...
    }

```

Within myMethod:, how do I convert the identifier from an id to an NSInteger?

I've seen this previous question:
[SEL performSelector and arguments](https://stackoverflow.com/questions/2716143/sel-performselector-and-arguments)

but I don't understand myMethodForNumber: - how is that used to unbox the number?