if err := api.Walk(ctx, r.Source.Bucket, prefix, prefixWalkCh, WalkOptions{
					Marker:   lastObject,
					Filter:   selectObj,
					AskDisks: walkQuorum,
				}); err != nil {
					cancelCause(err)
					xioutil.SafeClose(walkCh)
					return
				}
				for obj := range prefixWalkCh {
					walkCh <- obj
				}
			}
			xioutil.SafeClose(walkCh)
		}()

			return nil
		}

		if s.walkMu != nil {
			s.walkMu.Lock()
		}
		entries, err := s.ListDir(ctx, "", opts.Bucket, current, -1)
		if s.walkMu != nil {
			s.walkMu.Unlock()
		}
		if err != nil {
			// Folder could have gone away in-between
			if err != errVolumeNotFound && err != errFileNotFound {
				internalLogOnceIf(ctx, err, "metacache-walk-scan-dir")
			}

		f.walk(n.Body, ctxTypeSwitch, visit)
	case *ast.CommClause:
		f.walk(n.Comm, ctxStmt, visit)
		f.walk(n.Body, ctxStmt, visit)
	case *ast.SelectStmt:
		f.walk(n.Body, ctxStmt, visit)
	case *ast.ForStmt:
		f.walk(n.Init, ctxStmt, visit)
		f.walk(&n.Cond, ctxExpr, visit)
		f.walk(n.Post, ctxStmt, visit)
		f.walk(n.Body, ctxStmt, visit)
	case *ast.RangeStmt:
		f.walk(&n.Key, ctxExpr, visit)

}

func NewWalker(context *build.Context, root string) *Walker {
	w := &Walker{
		context:  context,
		root:     root,
		features: map[string]bool{},
		imported: map[string]*apiPackage{"unsafe": &apiPackage{Package: types.Unsafe}},
	}
	w.loadImports()
	return w
}

func (w *Walker) Features() (fs []string) {
	for f := range w.features {
		fs = append(fs, f)
	}

   * </pre>
   *
   * @throws IllegalArgumentException if there is a loop in the causal chain
   */
  public static Throwable getRootCause(Throwable throwable) {
    // Keep a second pointer that slowly walks the causal chain. If the fast pointer ever catches
    // the slower pointer, then there's a loop.
    Throwable slowPointer = throwable;
    boolean advanceSlowPointer = false;

    Throwable cause;

	switch n := x.(type) {
	default:
		error_(token.NoPos, "unexpected type %T in walk", x)
		panic("unexpected type")

	case *ast.IndexListExpr:
		f.walk(&n.X, ctxExpr, visit)
		f.walk(n.Indices, ctxExpr, visit)
	}
}

func funcTypeTypeParams(n *ast.FuncType) *ast.FieldList {
	return n.TypeParams
}

        val rootDirFiles = projectDir.resolve("build").walk().toList()

        archiveFileNames.forEach { fileName ->
            assertTrue(rootDirFiles.any { it.name == fileName })
        }
    }

    private
    fun assertLeftoverFilesCleanedUpEventually(vararg leftoverFiles: String) {
        leftoverFiles.forEach {
            assertTrue(projectDir.resolve(it).walk().filter { it.isFile }.toList().isEmpty())
        }

            if (logger.isDebugEnabled()) {
                logger.debug("{} does not exists.", dir);
            }
            return;
        }
        try (Stream<Path> walk = Files.walk(dir, FileVisitOption.FOLLOW_LINKS)) {
            walk.sorted(Comparator.reverseOrder()).forEach(f -> {
                if (logger.isDebugEnabled()) {
                    logger.debug("Deleting {}", f);
                }
                try {

        .listFiles()
        ?.associateWith { dir ->
            val dirPath = dir.toPath()
            Files.walk(dirPath).use { paths ->
                paths.filter { !it.toFile().isDirectory }
                    .limit(4)
                    .map { dirPath.relativize(it).toString() }
                    .collect(Collectors.toList())

        List<Path> poms;

        @Setup(Level.Iteration)
        public void setUp() throws IOException {
            Path userHome = Paths.get(System.getProperty("user.home"));
            poms = Files.walk(userHome.resolve(".m2/repository/org/apache/maven"))
                    .filter(p -> p.getFileName().toString().endsWith(".pom"))
                    .collect(Collectors.toList());
        }
    }

    @Benchmark