code: def test_download_data_target(
      wait_for_disk_usage_higher_than_threshold_mock, tmpdir
  ):
      input_dir = os.path.join(tmpdir, "input_dir")
      os.makedirs(input_dir, exist_ok=True)
  
      remote_input_dir = os.path.join(tmpdir, "remote_input_dir")
      os.makedirs(remote_input_dir, exist_ok=True)
  
      with open(os.path.join(remote_input_dir, "a.txt"), "w") as f:
          f.write("HERE")
  
      cache_dir = os.path.join(tmpdir, "cache_dir")
      os.makedirs(cache_dir, exist_ok=True)
  
      queue_in = mock.MagicMock()
  
      paths = [os.path.join(input_dir, "a.txt"), None]
  
      def fn(*_, **__):
          value = paths.pop(0)
          if value is None:
              return value
          return (0, [value])
  
      queue_in.get = fn
  
      queue_out = mock.MagicMock()
      _download_data_target(
          Dir(input_dir, remote_input_dir),
          cache_dir,
          queue_in,
          queue_out,
      )
  
      assert queue_out.put._mock_call_args_list[0].args == (0,)
      assert queue_out.put._mock_call_args_list[1].args == (None,)
  
      assert os.listdir(cache_dir) == ["a.txt"]
  
      wait_for_disk_usage_higher_than_threshold_mock.assert_called()
  
imports: import os
  import random
  import sys
  from typing import Any, List
  from unittest import mock
  import lightning_cloud
  import numpy
  import pytest
  import torch
  from lightning import seed_everything
  from lightning.data.streaming import data_processor
  from lightning.data.streaming import functions
  from lightning.data.streaming.cache import Cache, Dir
  from lightning.data.streaming.data_processor import DataChunkRecipe, DataProcessor, DataTransformRecipe, _download_data_target, _get_item_filesizes, _map_items_to_workers_sequentially, _map_items_to_workers_weighted, _remove_target, _upload_fn, _wait_for_disk_usage_higher_than_threshold, _wait_for_file_to_exist
  from lightning.data.streaming.functions import LambdaDataTransformRecipe, map, optimize
  from lightning_cloud import resolver
  from lightning_utilities.core.imports import RequirementCache
label_desc: Use image node_id 4 for calling a global function with example usage: test_download_data_target(wait_for_disk_usage_higher_than_threshold_mock, tmpdir) and returns: int,  list, value