code: def test_fileset_nested_structure(self, container: MetadataContainer):
      key = self.gen_key()
      possible_paths = self._gen_tree_paths(depth=3)
  
      small_files = [
          (
              f"{path}{uuid.uuid4()}.{fake.file_extension()}",
              os.urandom(random.randint(SIZE_1KB, 100 * SIZE_1KB)),
          )
          for path in possible_paths
      ]
  
      with tmp_context():
          # create dirs
          for dir_path in possible_paths:
              os.makedirs(dir_path, exist_ok=True)
          # create  a lot of very small files in different directories
          for filename, contents in small_files:
              with open(filename, "wb") as file:
                  file.write(contents)
  
          small_filenames = [filename for filename, _ in small_files]
          # make sure there are no duplicates
          assert len({*small_filenames}) == len(small_files)
  
          # when small files as fileset uploaded
          container[key].upload_files(".")
  
          # then check if everything will be downloaded
          container.sync()
          container[key].download("downloaded.zip")
  
          with ZipFile("downloaded.zip") as zipped:
              assert set(zipped.namelist()) == {
                  "/",
                  *possible_paths,
                  *small_filenames,
              }
              for filename, expected_content in small_files:
                  with zipped.open(filename, "r") as file:
                      content = file.read()
                      assert len(content) == len(expected_content)
                      assert content == expected_content
  
imports: import io
  import os
  import random
  import uuid
  from itertools import product
  from typing import Set
  from unittest.mock import Mock
  from zipfile import ZipFile
  import pytest
  from neptune.internal.backends import hosted_file_operations
  from neptune.internal.backends.api_model import MultipartConfig, OptionalFeatures
  from neptune.internal.backends.hosted_neptune_backend import HostedNeptuneBackend
  from neptune.internal.types.file_types import FileType
  from neptune.metadata_containers import MetadataContainer
  from neptune.types import File, FileSet
  from tests.e2e.base import AVAILABLE_CONTAINERS, BaseE2ETest, fake
  from tests.e2e.plot_utils import generate_altair_chart, generate_brokeh_figure, generate_matplotlib_figure, generate_pil_image, generate_plotly_figure, generate_seaborn_figure
  from tests.e2e.utils import SIZE_1KB, SIZE_1MB, initialize_container, preserve_cwd, tmp_context
label_desc: Use image node_id 5 for calling the TestFileSet obj's underlying member method code with example usage: obj.test_fileset_nested_structure(container) without return types