void (Statement stat) { if (stat.getExprents() == null) { for (Object obj : stat.getSequentialObjects()) { if (obj instanceof Statement) { setVersionsToNull((Statement)obj); } else if (obj instanceof Exprent) { setExprentVersionsToNull((Exprent)obj); } } } else { for (Exprent exprent : stat.getExprents()) { setExprentVersionsToNull(exprent); } } }