code: def test_generate(external_dataset):
      # Read from it using a plain reader
      with make_batch_reader(external_dataset.url) as reader:
          all_samples = list(reader)
      assert all_samples
  
file_path: petastorm/examples/hello_world/external_dataset/tests/test_generate_external_dataset.py
imports: import os
  import unittest
  import pytest
  from examples.hello_world.external_dataset.generate_external_dataset import generate_external_dataset
  from examples.hello_world.external_dataset.python_hello_world import python_hello_world
  from examples.hello_world.external_dataset.pytorch_hello_world import pytorch_hello_world
  from examples.hello_world.external_dataset.tensorflow_hello_world import tensorflow_hello_world
  from petastorm import make_batch_reader
  from petastorm.tests.conftest import SyntheticDataset
  from petastorm.tests.test_tf_utils import create_tf_graph
label_desc: Use image node_id 2 for calling a global function with example usage: test_generate(external_dataset) without return types