def METHOD_NAME(self, mocked_httpserver, _make_a_cached_fetcher):
    # Assert the fetcher (this trigger data fetching, hence caching as well):
    assert_fetcher(mocked_httpserver, _make_a_cached_fetcher, cacheable=True)
    # and we also make sure we can clear the cache:
    _make_a_cached_fetcher.clear_cache()
    with pytest.raises(CacheFileNotFound):
        _make_a_cached_fetcher.cachepath