def search(self, regex):
        try:
            spec = {'$or': [{'data.content'    : {'$regex': regex, '$options': 'im'}},
                            {'data.description': {'$regex': regex, '$options': 'im'}}]}
            fields = {'_id': 0}
            cur = self.db.docs.find(spec, fields)
        except Exception as e:
            raise DatabaseException(e)
        return [Document(**row) for row in cur]
async def handler(client, request):
		if request.path == "/v6/challenge":
			assert request.encode().decode() == CHALLENGE_REQUEST
			response = http.HTTPResponse(200)
			response.json = {
				"challenge": "vaNgVZZH7gUse0y3t8Cksuln-TAVtvBmcD-ow59qp0E=",
				"data": "dlL7ZBNSLmYo1hUlKYZiUA=="
			}
			return response
		else:
			assert request.encode().decode() == TOKEN_REQUEST
			response = http.HTTPResponse(200)
			response.json = {
				"device_auth_token": "device token"
			}
			return response