public function all($includingRead = false, $participating = false, DateTime $since = null, DateTime $before = null)
    {
        $parameters = [
            'all' => $includingRead,
            'participating' => $participating,
        ];

        if ($since !== null) {
            $parameters['since'] = $since->format(DateTime::ISO8601);
        }

        if ($before !== null) {
            $parameters['before'] = $before->format(DateTime::ISO8601);
        }

        return $this->get('/notifications', $parameters);
    }