code: def test_related_files(file, length, expected_files):
      related_files = get_related_files(file)
  
      assert len(related_files) == length
  
      for ef in expected_files:
          assert ef in related_files
  
imports: import os
  import time
  from pathlib import Path
  from unittest import mock, SkipTest
  import pytest
  from ...testing import TempFATFS
  from ...utils.filemanip import save_json, load_json, fname_presuffix, fnames_presuffix, hash_rename, check_forhash, _parse_mount_table, _cifs_table, on_cifs, copyfile, copyfiles, ensure_list, simplify_list, check_depends, split_filename, get_related_files, indirectory, loadpkl, loadcrash, savepkl, path_resolve, write_rst_list, emptydirs
label_desc: Use image node_id 21 for calling a global function with example usage: test_related_files(file, length, expected_files) without return types