def update(
            self, kb_id, update_kb, custom_headers=None, raw=False, **operation_config):
        """Asynchronous operation to modify a knowledgebase.

        :param kb_id: Knowledgebase id.
        :type kb_id: str
        :param update_kb: Post body of the request.
        :type update_kb:
         ~azure.cognitiveservices.knowledge.qnamaker.models.UpdateKbOperationDTO
        :param dict custom_headers: headers that will be added to the request
        :param bool raw: returns the direct response alongside the
         deserialized response
        :param operation_config: :ref:`Operation configuration
         overrides<msrest:optionsforoperations>`.
        :return: Operation or ClientRawResponse if raw=true
        :rtype: ~azure.cognitiveservices.knowledge.qnamaker.models.Operation
         or ~msrest.pipeline.ClientRawResponse
        :raises:
         :class:`ErrorResponseException<azure.cognitiveservices.knowledge.qnamaker.models.ErrorResponseException>`
        """
        # Construct URL
        url = self.update.metadata['url']
        path_format_arguments = {
            'Endpoint': self._serialize.url("self.config.endpoint", self.config.endpoint, 'str', skip_quote=True),
            'kbId': self._serialize.url("kb_id", kb_id, 'str')
        }
        url = self._client.format_url(url, **path_format_arguments)

        # Construct parameters
        query_parameters = {}

        # Construct headers
        header_parameters = {}
        header_parameters['Accept'] = 'application/json'
        header_parameters['Content-Type'] = 'application/json; charset=utf-8'
        if custom_headers:
            header_parameters.update(custom_headers)

        # Construct body
        body_content = self._serialize.body(update_kb, 'UpdateKbOperationDTO')

        # Construct and send request
        request = self._client.patch(url, query_parameters, header_parameters, body_content)
        response = self._client.send(request, stream=False, **operation_config)

        if response.status_code not in [202]:
            raise models.ErrorResponseException(self._deserialize, response)

        deserialized = None
        header_dict = {}

        if response.status_code == 202:
            deserialized = self._deserialize('Operation', response)
            header_dict = {
                'Location': 'str',
            }

        if raw:
            client_raw_response = ClientRawResponse(deserialized, response)
            client_raw_response.add_headers(header_dict)
            return client_raw_response

        return deserialized
Asynchronous operation to modify a knowledgebase.

        :param kb_id: Knowledgebase id.
        :type kb_id: str
        :param update_kb: Post body of the request.
        :type update_kb:
         ~azure.cognitiveservices.knowledge.qnamaker.models.UpdateKbOperationDTO
        :param dict custom_headers: headers that will be added to the request
        :param bool raw: returns the direct response alongside the
         deserialized response
        :param operation_config: :ref:`Operation configuration
         overrides<msrest:optionsforoperations>`.
        :return: Operation or ClientRawResponse if raw=true
        :rtype: ~azure.cognitiveservices.knowledge.qnamaker.models.Operation
         or ~msrest.pipeline.ClientRawResponse
        :raises:
         :class:`ErrorResponseException<azure.cognitiveservices.knowledge.qnamaker.models.ErrorResponseException>`