code: def main():
      # Make sure BASE_DIR ends with tensorflow.  If it doesn't, we probably
      # computed the wrong directory.
      if os.path.split(BASE_DIR)[-1] != "tensorflow":
          raise AssertionError(
              "BASE_DIR = '%s' doesn't end with tensorflow" % BASE_DIR
          )
  
      for dirpath, dirnames, filenames in os.walk(
          BASE_DIR, followlinks=True
      ):
          lowercase_directories = [x.lower() for x in dirnames]
          lowercase_files = [x.lower() for x in filenames]
  
          lowercase_dir_contents = (
              lowercase_directories + lowercase_files
          )
          if len(lowercase_dir_contents) != len(
              set(lowercase_dir_contents)
          ):
              raise AssertionError(ERROR_MESSAGE.format(dirpath))
  
label_desc: Use image node_id 1 for calling a global function with example usage: main() without return types