code: def test_create_cache_dir(self):
      @cache_results("demo/demo.pkl")
      def cache():
          return 1, 2
  
      try:
          results = cache()
          assert (1, 2) == results
      finally:
          rank_zero_rm("demo/")
  
imports: import os
  import pytest
  import subprocess
  from io import StringIO
  import sys
  from fastNLP.core.utils.cache_results import cache_results
  from fastNLP.envs.distributed import rank_zero_rm
label_desc: Use image node_id 9 for calling the TestCacheResults obj's underlying member method code with example usage: obj.test_create_cache_dir() and returns: int,  int