*
 * <p>If you have your own graph implementation based around a custom node type {@code MyNode},
 * which has a method {@code getParents()} that retrieves its predecessors in a graph:
 *
 * {@snippet :
 * someGraphAlgorithm(startNode, MyNode::getParents);
 * }
 *
 * <p>If you have some other mechanism for returning the predecessors of a node, or one that doesn't

      assertThat(root.getParent()).isNull();
      assertThat(root.toRealPath().getParent()).isNull();
      MoreFiles.createParentDirectories(root); // test that there's no exception
    }
  }

  public void testCreateParentDirectories_relativePath() throws IOException {
    Path path = FS.getPath("nonexistent.file");
    assertThat(path.getParent()).isNull();

                        Files.createDirectories(path.getParent());
                        Files.copy(zis, path, StandardCopyOption.REPLACE_EXISTING);
                    } else if ("css".equals(names[0])) {
                        names[0] = themeName;
                        final Path path = ResourceUtil.getCssPath(names);
                        Files.createDirectories(path.getParent());

      assertThat(root.getParent()).isNull();
      assertThat(root.toRealPath().getParent()).isNull();
      MoreFiles.createParentDirectories(root); // test that there's no exception
    }
  }

  public void testCreateParentDirectories_relativePath() throws IOException {
    Path path = FS.getPath("nonexistent.file");
    assertThat(path.getParent()).isNull();

                    }
                }
                try {
                    Files.delete(artifactPath);
                    Files.delete(artifactPath.getParent());
                    Files.delete(artifactPath.getParent().getParent());
                } catch (DirectoryNotEmptyException e) {
                    // ignore
                }
            }
        } catch (IOException e) {

            Files.createDirectories(basePath);
            final Path realBase = basePath.toRealPath();
            Files.createDirectories(filePath.getParent());
            final Path realParent = filePath.getParent().toRealPath();
            if (!realParent.startsWith(realBase)) {
                logger.warn("Symlink traversal detected: url={}, realParent={}, realBase={}", url, realParent, realBase);

  }

  private WeakReference<ClassLoader> useFrqInSeparateLoader() throws Exception {
    ClassLoader myLoader = getClass().getClassLoader();
    URLClassLoader sepLoader = new URLClassLoader(getClassPathUrls(), myLoader.getParent());
    // sepLoader is the loader that we will use to load the parallel FinalizableReferenceQueue (FRQ)
    // and friends, and that we will eventually expect to see garbage-collected. The assumption

                    logger.debug("Deleted thumbnail file: {}", path);
                }

                Path parent = path.getParent();
                while (deleteEmptyDirectory(parent)) {
                    parent = parent.getParent();
                }
            } catch (final IOException e) {
                logger.warn("Failed to delete thumbnail file: {}", path, e);
            }

        return new File(artifact.getFile().getParentFile(), sb.toString());
    }

    File getTouchfile(RepositoryMetadata metadata, File file) {
        return new File(file.getParent(), TOUCHFILE_NAME);
    }

  }

  private WeakReference<ClassLoader> useFrqInSeparateLoader() throws Exception {
    ClassLoader myLoader = getClass().getClassLoader();
    URLClassLoader sepLoader = new URLClassLoader(getClassPathUrls(), myLoader.getParent());
    // sepLoader is the loader that we will use to load the parallel FinalizableReferenceQueue (FRQ)
    // and friends, and that we will eventually expect to see garbage-collected. The assumption