get_resource_value: Wrong error returned when accessing not-existing device

[dimagr-arm]

I installed the SDK using pip install command on my Windows PC.
I call get_resource_value API as described below:

api = ConnectAPI()
api.start_notifications()
value = api.get_resource_value(DEVICE_ID, WRITEABLE_RESOURCE)

If the DEVICE_ID string pointing to the not-existing device, the following error happens:

  File "set-resource-dima.py", line 33, in _main
    value = api.get_resource_value(DEVICE_ID, WRITEABLE_RESOURCE)
  File "C:\Python27\lib\site-packages\mbed_cloud\decorators.py", line 33,
in wrapped_f
    return fn(*args, **kwargs)
  File "C:\Python27\lib\site-packages\mbed_cloud\connect\connect.py", line
 302, in get_resource_value
    return self.get_resource_value_async(device_id, resource_path, fix_pat
h).wait(timeout)
AttributeError: 'NoneType' object has no attribute 'wait'

I expect to get a specific exception in this case and not AttributeError exception.

Note: if the DEVICE_ID string pointing to the existing device, the correct value is returned.