def _special_method_cache(method, cache_wrapper):
    """
    Because Python treats special methods differently, it's not
    possible to use instance attributes to implement the cached
    methods.

    Instead, install the wrapper method under a different name
    and return a simple proxy to that wrapper.

    https://github.com/jaraco/jaraco.functools/issues/5
    """
    name = method.__name__
    special_names = '__getattr__', '__getitem__'
    if name not in special_names:
        return

    wrapper_name = '__cached' + name

    def proxy(self, *args, **kwargs):
        if wrapper_name not in vars(self):
            bound = types.MethodType(method, self)
            cache = cache_wrapper(bound)
            setattr(self, wrapper_name, cache)
        else:
            cache = getattr(self, wrapper_name)
        return cache(*args, **kwargs)

    return proxy

    Because Python treats special methods differently, it's not
    possible to use instance attributes to implement the cached
    methods.

    Instead, install the wrapper method under a different name
    and return a simple proxy to that wrapper.

    https://github.com/jaraco/jaraco.functools/issues/5
    
product/gradle-plugin/src/main/python/pkg_resources/_vendor/jaraco/functools.py