I want to set arrayCollection #2 = to arrayCollection #1 via a function in flex 3. I pass both array collections to a function and set arrayCollection #2 = arrayCollection #1. However, it seems to not be passing arrayCollection #2 by reference because after the function call, arrayCollection #2 has not been changed. My understanding is that it should be passed by reference and work, am I doing something wrong? Below is the code:

```
var AC1:ArrayCollection = new ArrayCollection;
var AC1.addItem(someObject);

var AC2:ArrayCollection = new ArrayCollection;

setAC2(AC1,AC2);
// AC2 is not set to AC1 after the function

private function setAC2(_ac1:ArrayCollection, _ac2:ArrayCollection):void
{
    _ac2 = _ac1;
}

```