Hi all, It seems that there are more and more users from user mailing list ask how to do unit test with Flink features like states or timer. And the community usually tends to suggest them using `AbstractStreamOperator` and provide an example from Flink github repo. Here I sort out some examples and write them down in the testing documentation [1]. And I would link to contribute back to the Flink.
The reason why I ask it first in dev mailing list is that `AbstractStreamOperator` is an internal API and could be changed at any time. I'm not sure if it is worth to provide these examples on testing document, so I want to collect some feedbacks before I go to open a JIRA ticket. If this is feasible and valuable, then I will open the corresponding JIRA ticket and we can discuss more details of what examples are good to have in the document or how to structure the content. I would really appreciate any feedback from you. Thanks in advance. Best Regards, Tony Wei [1] https://github.com/apache/flink/compare/master...tony810430:flink-testing-doc
