code: def ensure_versions_dir_exists(tfenv_path):
      
      versions_dir = os.path.join(tfenv_path, 'versions')
      if not os.path.isdir(tfenv_path):
          os.mkdir(tfenv_path)
      if not os.path.isdir(versions_dir):
          os.mkdir(versions_dir)
      return versions_dir
docs: Ensure versions directory is available.