title: Action Script Prototypes and dynamic function creation
body: <p>Does anyone know how AS3/Flash runtime handles trying to modify the prototype  when working between sandboxes.  In particular I create object O in sandbox A, then pass it to SandBox B.  What is the effect if code in sandbox B tries to modify the prototype ? (do the objects in A of the same class see this ?).  Can Sandbox B overwrite public fields and methods of the object created in sandbox A  ( if the object is passed in as a param)? Is it possible to create an unmodifiable class (ie. the equivalent of say final in java) that can act as a ready only proxy to pass between loaded swf's and the main swf ?  I know the event class can use clone() to sort of do this, and then pass the events between the 2 swf's.  Is using a final class in AS3 the right way to create read only proxies that can't be modified at all ?</p>