child in PRAddCommand question

Hi, I'm using pier in a project who needs execute certain operations after a command is executed (journal/persistence stuff) and I added a method PRCommand, who is executed after doExecute... so... what is the problem? well, I have to mark an object as "persistent", in PRAddCommand, and then I do: self child bePersistent... but, as #child answer a ew instance of #type, the operation is lost... I changed #child to use an instVar and just instantiate once.... everything seems to be working now, but I want to know if there is a possible problem with this change... what do you think? the change works? Thanks, Esteban