public function failedRequest(Response $response)
    {
        // Decode Response.
        $decodedResponse = json_decode($response->getBody()->getContents(), true);
        // Get error message.
        $errorMessage = (isset($decodedResponse['error_message']) && ! is_null($decodedResponse['error_message'])) ? $decodedResponse['error_message'] : $response->getReasonPhrase();
        // ClientException.
        throw new WatsonBridgeException($errorMessage, $response->getStatusCode());
    }