.containsExactly(rootDir, fileA, fileB, dir1, dir2);
  }

  @CanIgnoreReturnValue
  private File newDir(String name) {
    File file = new File(rootDir, name);
    file.mkdir();
    return file;
  }

  @CanIgnoreReturnValue
  private File newFile(String name) throws IOException {
    File file = new File(rootDir, name);
    file.createNewFile();
    return file;
  }

        .containsExactly(rootDir, fileA, fileB, dir1, dir2);
  }

  @CanIgnoreReturnValue
  private File newDir(String name) {
    File file = new File(rootDir, name);
    file.mkdir();
    return file;
  }

  @CanIgnoreReturnValue
  private File newFile(String name) throws IOException {
    File file = new File(rootDir, name);
    file.createNewFile();
    return file;
  }