Procedure append_events has unused variables:

• @newMessagesCount INT
• @expected_StreamVersionAfterUpdate INT
• @actual_StreamVersionAfterUpdate INT

This results in static code analysis build errors

SqlServer.Rules : Variable '@actual_StreamVersionAfterUpdate' is declared but never referenced or assigned. (https://github.com/ErikEJ/SqlServer.Rules/blob/master/docs/Design/SRD0012.md)