When the business key is set for first topic and it's not for the second. For example:
Fetching the external tasks for both topics.
Only the tasks from the first topic are returned, the others are disregarded.
- With the current implementation the business key of the second topic is set to null.
parameter.businessKeyFilter should be replaced by topicFilters.businessKey
- The implementation could be simplified and filterBybusinessKey could be removed.