final StringBuffer buffer = writer.getBuffer();
buffer.delete(0, buffer.length());
ValueStack newStack = container.getInstance(ValueStackFactory.class).createValueStack();
newStack.getContext().put(ActionContext.LOCALE, foreignLocale);
newStack.getContext().put(ActionContext.CONTAINER, container);
newStack.push(new TestAction1());
request.setAttribute(ServletActionContext.STRUTS_VALUESTACK_KEY, newStack);
assertNotSame(ActionContext.getContext().getValueStack().peek(), newStack.peek());
tag.doStartTag();
tag.doEndTag();