code: def simple_cache(func):
      
      saved_results = {}
  
      def wrapper(cls, module):
          if module in saved_results:
              return saved_results[module]
          saved_results[module] = func(cls, module)
          return saved_results[module]
      return wrapper
docs: Save results for the :meth:'path.using_module' classmethod.
      When Python 3.2 is available, use functools.lru_cache instead.