code: def test_num_cuda_devices_without_nvml(*_):
      """Test that if NVML can't be loaded, our helper functions fall back to the default implementation for determining
      CUDA availability."""
      num_cuda_devices.cache_clear()
      assert is_cuda_available()
      assert num_cuda_devices() == 100
      num_cuda_devices.cache_clear()
  
file_path: pytorch-lightning/tests/tests_fabric/accelerators/test_cuda.py
imports: import importlib
  import logging
  import os
  from re import escape
  from unittest import mock
  from unittest.mock import Mock
  import lightning.fabric
  import pytest
  import torch
  from lightning.fabric.accelerators.cuda import CUDAAccelerator, _check_cuda_matmul_precision, find_usable_cuda_devices, is_cuda_available, num_cuda_devices
  from tests_fabric.helpers.runif import RunIf
label_desc: Use image node_id 6 for calling a global function with example usage: test_num_cuda_devices_without_nvml() without return types