changing = liftPipelineChildren(self) || changing;
changing = liftChildren(self) || changing;
    public void preVisitSplitJoin(SIRSplitJoin self,				  SIRSplitJoinIter iter) {	boolean changing;	do {	    changing = false;	    changing = liftPipelineChildren(self) || changing;	    changing = liftIntoSplitJoin(self) || changing;	} while (changing);    }