Get the global rate limit per client.

        :rtype: int
        :returns: The global rate limit for each client.

def get_global_rate_limit(self):
        """Get the global rate limit per client.

        :rtype: int
        :returns: The global rate limit for each client.
        """
        r = urllib.request.urlopen('https://archive.org/metadata/iamine-rate-limiter')
        j = json.loads(r.read().decode('utf-8'))
        return int(j.get('metadata', {}).get('rate_per_second', 300))