Object previous = (stack != null && !stack.empty()) ? stack.pop() : null; request.setAttribute(StripesConstants.REQ_ATTR_ACTION_BEAN, previous);
if (stack != null && !stack.empty()) { request.setAttribute(StripesConstants.REQ_ATTR_ACTION_BEAN, stack.pop()); }
    protected void restoreActionBean(HttpServletRequest request) {        Stack stack = getActionBeanStack(request, false);        Object previous = (stack != null && !stack.empty()) ? stack.pop() : null;        request.setAttribute(StripesConstants.REQ_ATTR_ACTION_BEAN, previous);    }