Hi team, I'm currently implementing a custom source and sink, and I'm trying to find a way to test these implementations. The testing section <https://ci.apache.org/projects/flink/flink-docs-release-1.13/docs/dev/datastream/testing/#unit-testing-stateful-or-timely-udfs--custom-operators> in the official doc seems to only include testing for stateful/stateless operators. Do you have any recommendations on how I should approach this?
Thanks Bin
