code: def testWalk(self):
      temp_dir = self._CreateDeepS3Structure()
      self._CreateDeepS3Structure(temp_dir)
      expected = [
          [
              "",
              [
                  "a.tfevents.1",
                  "model.ckpt",
              ],
          ],
          # Empty directory not returned
          # ['foo', []],
          [
              "bar",
              [
                  "b.tfevents.1",
                  "red_herring.txt",
              ],
          ],
          [
              "bar/baz",
              [
                  "c.tfevents.1",
                  "d.tfevents.1",
              ],
          ],
          [
              "bar/quux",
              [
                  "some_flume_output.txt",
                  "some_more_flume_output.txt",
              ],
          ],
          [
              "quuz",
              [
                  "e.tfevents.1",
              ],
          ],
          [
              "quuz/garply",
              [
                  "f.tfevents.1",
              ],
          ],
          [
              "quuz/garply/corge",
              [
                  "g.tfevents.1",
              ],
          ],
          [
              "quuz/garply/grault",
              [
                  "h.tfevents.1",
              ],
          ],
          ["waldo", []],
          [
              "waldo/fred",
              [
                  "i.tfevents.1",
              ],
          ],
      ]
      for pair in expected:
          # If this is not the top-level directory, prepend the high-level
          # directory.
          pair[0] = (
              self._PathJoin(temp_dir, pair[0]) if pair[0] else temp_dir
          )
      gotten = gfile.walk(temp_dir)
      self._CompareFilesPerSubdirectory(expected, gotten)
  
imports: import boto3
  import os
  import unittest
  from moto import mock_s3
  from tensorboard.compat.tensorflow_stub import errors
  from tensorboard.compat.tensorflow_stub.io import gfile
label_desc: Use image node_id 7 for calling the GFileTest obj's underlying member method code with example usage: obj.testWalk() without return types