Description
In gremlin-python driver versions 3.5.2 and 3.5.3, the client.submit_async() function was added and the client.submitAsync() function was changed to call into it and warn about future deprecation.
The line in submitAsync which invokes the new function submit_async does not return the future back to the caller, resulting in the caller receiving a None object.
This in turn means that an application which upgrades from 3.4.x to latest 3.5.x will break when trying to read result from the response future.
> AttributeError: 'NoneType' object has no attribute 'result'
This issue is fixed in 3.6.x with the addition of an explicit return statement, but has persisted from driver version 3.5.2 to 3.5.3.