code: def check_installation(cur_file):
      """Warn user if running cleverhans from a different directory than tutorial."""
      cur_dir = os.path.split(
          os.path.dirname(os.path.abspath(cur_file))
      )[0]
      ch_dir = os.path.split(cleverhans.__path__[0])[0]
      if cur_dir != ch_dir:
          warnings.warn(
              "It appears that you have at least two versions of "
              "cleverhans installed, one at %s and one at"
              " %s. You are running the tutorial script from the "
              "former but python imported the library module from the "
              "latter. This may cause errors, for example if the tutorial"
              " version is newer than the library version and attempts to"
              " call new features." % (cur_dir, ch_dir)
          )
  
label_desc: Use image node_id 1 for calling a global function with example usage: check_installation(cur_file) without return types