private boolean goBack(Command command){
        int backage = 0;
        if(!command.hasNthWord(2)){
            backage = 1;
        } else {
            String sWord = command.getNthSegment(1);
            try {
                backage = Integer.parseInt(sWord);
            } catch(NumberFormatException e) {
                return false;
            }
        }
        if(previousRooms.size() < backage) {
            return false;
        }
        ArrayList<String> roomsToGo = new ArrayList<String>(backage);
        for (int i = 1; i <= backage; i++) {
            roomsToGo.add(previousRooms.get(previousRooms.size()-i));
        }
        for (int i = 0; i < roomsToGo.size()-1; i ++) {
            previousRooms.add(roomsToGo.remove(i));
        }
        goRoom(roomsToGo.remove(0));
        return true;
    }