private File root;
private File relativeNonExist;
@Before
public void createFiles() throws IOException {
final TemporaryFolder temp = new TemporaryFolder();
temp.create();
root = temp.getRoot();
temp.newFile("hoge.txt");
temp.newFile("photo1.jpg");
temp.newFile("photo2.jpg");
final File sub = temp.newFolder("sub");
final File file1 = temp.newFile("photo3.jpg");
final File file2 = temp.newFile("photo4.jpg");
file1.renameTo(new File(sub.getAbsolutePath() + File.separator + file1.getName()));
file2.renameTo(new File(sub.getAbsolutePath() + File.separator + file2.getName()));
relativeNonExist = new File("./relative" + System.nanoTime() + ".txt");
}