code: def check_notebook_list(contents, workflow):
      marker_line = find_marker_line(contents, NOTEBOOK_MARKER)
  
      found = find_key(
          workflow,
          ["jobs", NOTEBOOK_JOB, "strategy", "matrix", "notebook"],
          marker_line,
      )
      expected = set(glob.glob("demos/**/*.ipynb", recursive=True))
  
      unique_and_equal(
          found,
          expected,
          name="notebook(s)",
          step=NOTEBOOK_JOB,
          marker_line=marker_line,
      )
  
file_path: stellargraph/scripts/ci/validate_ci_workflow.py
imports: import yaml
  import sys
  import glob
  import os
  from collections import Counter
label_desc: Use image node_id 5 for calling a global function with example usage: check_notebook_list(contents, workflow) without return types