code: def test_is_shared_filesystem(tmp_path, monkeypatch):
      # In the non-distributed case, every location is interpreted as 'shared'
      assert is_shared_filesystem(
          SingleDeviceStrategy(torch.device("cpu"))
      )
  
      test_fn = functools.partial(
          _test_is_shared_filesystem,
          tmp_path=tmp_path,
          monkeypatch=monkeypatch,
      )
      spawn_launch(test_fn, [torch.device("cpu"), torch.device("cpu")])
  
imports: import functools
  import os
  from functools import partial
  from pathlib import Path
  from unittest import mock
  import pytest
  import torch
  from lightning.fabric.accelerators import CPUAccelerator, CUDAAccelerator, MPSAccelerator
  from lightning.fabric.plugins.environments import LightningEnvironment
  from lightning.fabric.strategies import DDPStrategy, SingleDeviceStrategy
  from lightning.fabric.strategies.launchers.multiprocessing import _MultiProcessingLauncher
  from lightning.fabric.utilities.distributed import _gather_all_tensors, _set_num_threads_if_needed, _suggested_max_num_threads, _sync_ddp, is_shared_filesystem
  from tests_fabric.helpers.runif import RunIf
label_desc: Use image node_id 7 for calling a global function with example usage: test_is_shared_filesystem(tmp_path, monkeypatch) without return types