'BatchServiceClientConfiguration' object has no attribute 'signed_session'

Get "'BatchServiceClientConfiguration' object has no attribute 'signed_session'" exception when creating pool with the following Python code.

> new_pool = batch.models.PoolAddParameter(
> id='GPU-Pool',
> virtual_machine_configuration=batch.models.VirtualMachineConfiguration(
> image_reference=image_ref_to_use,
> container_configuration=container_conf,
> node_agent_sku_id='batch.node.ubuntu 16.04'),
> vm_size='Standard_NC6',
> target_low_priority_nodes=1)
> batch_client.pool.add(new_pool)

I'm using the following related python packages under Python 3.7:

> azure-batch==8.0.0
> azure-common==1.1.23
> azure-nspkg==3.0.2
> azure-storage==0.36.0
> msrestazure==0.6.2

Please advise, thanks!

The complete exception stack is like:

> ---------------------------------------------------------------------------
> AttributeError Traceback (most recent call last)
> in ()
> 7 vm_size='Standard_NC6',
> 8 target_low_priority_nodes=1)
> ----> 9 batch_client.pool.add(new_pool)
>
> /anaconda3/lib/python3.7/site-packages/azure/batch/operations/_pool_operations.py in add(self, pool, pool_add_options, custom_headers, raw, **operation_config)
> 320 # Construct and send request
> 321 request = self._client.post(url, query_parameters, header_parameters, body_content)
> --> 322 response = self._client.send(request, stream=False, **operation_config)
> 323
> 324 if response.status_code not in [201]:
>
> /anaconda3/lib/python3.7/site-packages/msrest/service_client.py in send(self, request, headers, content, **kwargs)
> 334 kwargs.setdefault('stream', True)
> 335 try:
> --> 336 pipeline_response = self.config.pipeline.run(request, **kwargs)
> 337 # There is too much thing that expects this method to return a "requests.Response"
> 338 # to break it in a compatible release.
>
> /anaconda3/lib/python3.7/site-packages/msrest/pipeline/__init__.py in run(self, request, **kwargs)
> 195 pipeline_request = Request(request, context) # type: Request[HTTPRequestType]
> 196 first_node = self._impl_policies[0] if self._impl_policies else self._sender
> --> 197 return first_node.send(pipeline_request, **kwargs) # type: ignore
> 198
> 199 class HTTPSender(AbstractContextManager, ABC, Generic[HTTPRequestType, HTTPResponseType]):
>
> /anaconda3/lib/python3.7/site-packages/msrest/pipeline/__init__.py in send(self, request, **kwargs)
> 148 self._policy.on_request(request, **kwargs)
> 149 try:
> --> 150 response = self.next.send(request, **kwargs)
> 151 except Exception:
> 152 if not self._policy.on_exception(request, **kwargs):
>
> /anaconda3/lib/python3.7/site-packages/msrest/pipeline/requests.py in send(self, request, **kwargs)
> 63 session = request.context.session
> 64 try:
> ---> 65 self._creds.signed_session(session)
> 66 except TypeError: # Credentials does not support session injection
> 67 _LOGGER.warning("Your credentials class does not support session injection. Performance will not be at the maximum.")
>
> AttributeError: 'BatchServiceClientConfiguration' object has no attribute 'signed_session'