code: def test_train(self) -> None:
      for use_gpu in {False, torch.cuda.is_available()}:
          folder = f"{self.base_dir}/train_test/{use_gpu}"
          os.makedirs(folder)
  
          task = build_task(
              get_fast_test_task_config(head_num_classes=2)
          )
  
          csv_hook = OutputCSVHook(folder)
          task.set_hooks([csv_hook])
          task.set_use_gpu(use_gpu)
  
          trainer = LocalTrainer()
          trainer.train(task)
  
          self.assertEqual(parse_csv(csv_hook.output_path), 10)
  
file_path: ClassyVision/test/hooks_output_csv_hook_test.py
imports: import csv
  import os
  import shutil
  import tempfile
  import torch
  from classy_vision.hooks import OutputCSVHook
  from classy_vision.tasks import build_task
  from classy_vision.trainer import LocalTrainer
  from test.generic.config_utils import get_fast_test_task_config
  from test.generic.hook_test_utils import HookTestBase
label_desc: Use image node_id 4 for calling the TestCSVHook obj's underlying member method code with example usage: obj.test_train() without return types