private List<List<String>> extractTargetLines(String station1,
            String station2) {
        List<List<String>> target = new ArrayList<List<String>>();
        for (List<String> line : lines) {
            if (line.contains(station1) || line.contains(station2)) {
                if (!target.contains(line)) {
                    target.add(line);
                }
            }
        }
        return target;
    }