code: def test_cases():
      """This is called by test.py to build up the test cases."""
      TMTestCase.generate_tests()
      yield TMTestCase
      MarkdownTestTestCase.generate_tests()
      yield MarkdownTestTestCase
      PHPMarkdownTestCase.generate_tests()
      yield PHPMarkdownTestCase
      PHPMarkdownExtraTestCase.generate_tests()
      yield PHPMarkdownExtraTestCase
      yield DirectTestCase
      yield DocTestsTestCase
  
imports: import os
  import sys
  from os.path import join, dirname, abspath, exists, splitext, basename
  import re
  from glob import glob
  import unittest
  import codecs
  import difflib
  import doctest
  from json import loads
label_desc: Use image node_id 11 for calling a global function with example usage: test_cases() without return types