public function getTransient(string $setting = '')
    {
        $data = $this->get();
        $settings = $data['transient'];

        if ('' !== $setting) {
            if (isset($settings[$setting])) {
                return $settings[$setting];
            }

            if (false !== \strpos($setting, '.')) {
                // convert dot notation to nested arrays
                $keys = \explode('.', $setting);
                foreach ($keys as $key) {
                    if (isset($settings[$key])) {
                        $settings = $settings[$key];
                    } else {
                        return null;
                    }
                }

                return $settings;
            }

            return null;
        }

        return $settings;
    }