def METHOD_NAME(self, key):
    settings_manager = SettingsManager()
    set_proxy_mock = MagicMock()
    settings_manager.set_proxy = set_proxy_mock
    settings_proxy_resource = SettingsProxy(settings_manager)
    self.api.add_route(self.api_url, settings_proxy_resource)
    self.simulate_request(self.api_url, decode='utf-8', method='DELETE', query_string="key="+key)
    self.assertEqual(self.srmock.status, falcon.HTTP_NO_CONTENT)
    set_proxy_mock.assert_called_once_with(key, None)