code: def test_build_config_dockerfile_provided():
      spec = BuildConfig(dockerfile="./projects/Dockerfile.cpu")
      assert not spec.requirements
      # ugly hack due to replacing `pytorch_lightning string
      assert (
          "pytorchlightning/pytorch_lightning"
          in spec.dockerfile.data[0]
      )
  
imports: import logging
  import os
  import sys
  from unittest.mock import Mock
  from lightning.app.testing import LightningTestApp, application_testing
  from lightning.app.utilities.packaging.build_config import BuildConfig
  from tests_app import _TESTS_ROOT
label_desc: Use image node_id 4 for calling a global function with example usage: test_build_config_dockerfile_provided() without return types