def METHOD_NAME(self):
    self.plugin.storage.put("testkey", "testvalue")
    # Write to disk
    self.plugin.storage.save()
    with mock.patch("certbot.reverter.util"):
        another = self.plugin_cls(self.config, "mockplugin")
    assert another.storage.fetch("testkey") == "testvalue"
    with open(os.path.join(self.config.config_dir,
                           ".pluginstorage.json"), 'r') as fh:
        psdata = fh.read()
    psjson = json.loads(psdata)
    assert "mockplugin" in psjson.keys()
    assert len(psjson) == 1
    assert psjson["mockplugin"]["testkey"] == "testvalue"