if (context.get()==null) newContext(); LinkedList l = (LinkedList) context.get(); Object last = l.removeLast();
Object last = _context.removeLast();
	protected void pop(Object o){		if (context.get()==null) newContext();		LinkedList l = (LinkedList) context.get();		Object last = l.removeLast();		if (o != last){			throw new IllegalStateException("Context is invalid. Trying to remove Object "+o+" and removed Object "+last);		}	}