* then recursively filling the new hole created.
     *
     * @return the position of the new hole (where the lowest grandchild moved from, that had no
     *     grandchild to replace it)
     */
    int fillHoleAt(int index) {
      int minGrandchildIndex;
      while ((minGrandchildIndex = findMinGrandChild(index)) > 0) {

    // directory with a cycle,
    // /root
    //    /child
    //       /[grandchild -> root]
    Path root = createTempDirectory("ClassPathTest");
    try {
      createFile(root.resolve("some.txt"));
      Path child = createDirectory(root.resolve("child"));
      createSymbolicLink(child.resolve("grandchild"), root);
      assertEquals(
          ImmutableSet.of(new ResourceInfo(FILE, "some.txt", loader)),