The principal predicates new/2, send/[2-12] and get/[3-13] will destroy all argument- and answer- objects created during their execution except for the object created by new/2 and the object returned by get/[3-13].
An object created by new/2 
with an integer (anonymous) object reference must either be attached to 
another object, locked against PCE's garbage collector or destroyed 
using `object->done' 
if it is created during the
initialisation of the application or in a loop that is passed 
many times. Such objects will be automatically reclaimed if (1) the 
object is created while handling a user-event after handling the event 
is finished or (2) the object is created in the implementation of a 
method on a user-defined class and the method terminates execution.
If is is not known whether or not the result of get/[3-13] 
is a computed object the user should invoke `object->done' 
to this result when the result is no longer needed. This will free the 
result if it was a computed (and no longer referenced) object and has no 
effect otherwise. If the result of the get operation is known to be an 
integer, no such message should be send.