code: def test_get_folder_size(tmpdir):
      array = np.zeros((10, 10))
  
      np.save(os.path.join(tmpdir, "array_1.npy"), array)
      np.save(os.path.join(tmpdir, "array_2.npy"), array)
  
      assert _get_folder_size(tmpdir) == 928 * 2
  
file_path: pytorch-lightning/tests/tests_data/streaming/test_reader.py
imports: import os
  import shutil
  from time import sleep
  import numpy
  from lightning.data.streaming import reader
  from lightning.data.streaming.cache import Cache
  from lightning.data.streaming.config import ChunkedIndex
  from lightning.data.streaming.item_loader import PyTreeLoader
  from lightning.data.streaming.reader import _END_TOKEN, PrepareChunksThread, _get_folder_size
  from lightning_cloud.resolver import Dir
label_desc: Use image node_id 2 for calling a global function with example usage: test_get_folder_size(tmpdir) without return types