private void diskQuadtreeTest(String fileName, Boundary boundaray) {

    // line of sample file is 100. And 2-Dimension,;

    QuadTreeFile quadTree = new QuadTreeFile(50, boundaray, "Q");

    int count = 0;
    try {

      BufferedReader in = new BufferedReader(new FileReader(fileName));

      String line;
      try {
        while ((line = in.readLine()) != null) {

          Point point = Point.stringToPoint(line);

          quadTree.insert(point);
          count++;
          assertEquals(count, quadTree.size());
        }

      } catch (IOException e) {
        e.printStackTrace();
      }

    } catch (FileNotFoundException e) {
      System.err.println(fileName + "is not existed in " + System.getProperty("user.dir"));
      e.printStackTrace();
    }

    quadTree.save();
    quadTree = QuadTreeFile.load("Q");

    int pointSizes = 0;
    List<QuadTree> leaves = quadTree.leaves();

    for (QuadTree leaf : leaves) {
      Iterator<Point> points = leaf.points();

      while (points.hasNext()) {
        points.next();

        pointSizes++;
      }
    }

    assertEquals(100, pointSizes);
  }
 @After
 public void delete() {
   QuadTreeFile.delete("Q");
 }