def get(self, id, pk='id', deleted=False):
        try:
            if pk == 'id':
                id = int(id)
            if deleted:
                spec = {pk: id}
            else:
                spec = {pk: id, 'data': {'$exists': 1}}
            fields = {'_id': 0}
            row = self.db.docs.find_one(spec, fields)
        except Exception as e:
            raise DatabaseException(e)
        if row:
            return Document(**row)
        raise NotFoundError('%s %s not found' % (pk, id))
def _loadapp(self, proxy_config_path):
        """
        Load a proxy from an app.conf to get the memcache_ring

        :returns: the memcache_ring of the memcache middleware filter
        """
        with mock.patch('swift.proxy.server.Ring'):
            app = loadapp(proxy_config_path)
        memcache_ring = None
        while True:
            memcache_ring = getattr(app, 'memcache', None)
            if memcache_ring:
                break
            app = app.app
        return memcache_ring