code: def test_csv_correct(nb):
      if os.getenv("OS") == "Windows_NT" and sys.version_info[0] == 2:
          pytest.skip(
              "tests with Python 2.7 on Windows are not stable in the CI environment. "
          )
      testCells = [
          cell for cell in nb.cells if cell.cell_type == "code"
      ]
      assert len(testCells) == 6
      text = get_output_stream_from_cell(testCells[5])
      print(text)
      assert re.search(expectedOutput, text)
  
imports: import os
  import re
  import sys
  import pytest
  from nb_helper import get_output_stream_from_cell
label_desc: Use image node_id 2 for calling a global function with example usage: test_csv_correct(nb) without return types