// We only scan each file once independent of the classloader that file might be
          // associated with.
          if (scannedUris.add(path.getCanonicalFile())) {
            scan(path, scannedUris, builder);
          }
        }
        scanJarFile(jarFile, builder);
      } finally {
        try {
          jarFile.close();

    File file = root();
    assertNull(file.getParentFile());
    assertNull(file.getCanonicalFile().getParentFile());
    Files.createParentDirs(file);
  }

  public void testCreateParentDirs_relativePath() throws IOException {
    File file = file("nonexistent.file");
    assertNull(file.getParentFile());
    assertNotNull(file.getCanonicalFile().getParentFile());
    Files.createParentDirs(file);
  }

    File file = root();
    assertNull(file.getParentFile());
    assertNull(file.getCanonicalFile().getParentFile());
    Files.createParentDirs(file);
  }

  public void testCreateParentDirs_relativePath() throws IOException {
    File file = file("nonexistent.file");
    assertNull(file.getParentFile());
    assertNotNull(file.getCanonicalFile().getParentFile());
    Files.createParentDirs(file);
  }

        Model model = new Model();
        model.setBuild(build);

        MavenProject project = new MavenProject(model);
        project.setFile(new File("pom.xml").getCanonicalFile());

        ExpressionEvaluator expressionEvaluator = createExpressionEvaluator(project, null, new Properties());

        Object value = expressionEvaluator.evaluate("${project.build.directory}/classes");

        Model model = new Model();
        model.setBuild(build);

        MavenProject project = new MavenProject(model);
        project.setFile(new File("pom.xml").getCanonicalFile());

        ExpressionEvaluator expressionEvaluator = createExpressionEvaluator(project, new Properties());

        Object value = expressionEvaluator.evaluate("${project.build.directory}/classes");

   *     directories of the specified file could not be created.
   * @since 4.0
   */
  public static void createParentDirs(File file) throws IOException {
    checkNotNull(file);
    File parent = file.getCanonicalFile().getParentFile();
    if (parent == null) {
      /*
       * The given directory is a filesystem root. All zero of its ancestors exist. This doesn't