protected function _redirect(ServerRequest $request, Response $response) {
		$message = $request->getSession()->consume($this->_config['flashKey']);
		$url = $response->getHeader('Location')[0];
		$status = $response->getStatusCode();

		$json = JsonEncoder::encode([
			// Error and content are here to make the output the same as previously
			// with the component, so existing unit tests don't break.
			'error' => null,
			'content' => null,
			'_message' => $message,
			'_redirect' => compact('url', 'status'),
		], $this->_config['jsonOptions']);

		$response = $response->withStatus(200)
			->withoutHeader('Location')
			->withHeader('Content-Type', 'application/json; charset=' . $response->getCharset())
			->withStringBody($json);

		return $response;
	}