code: public int updateManualBaseline(DbSession dbSession, String uuid, @Nullable String analysisUuid) {
      long now = system2.now();
      return mapper(dbSession).updateManualBaseline(uuid, analysisUuid == null || analysisUuid.isEmpty() ? null : analysisUuid, now);
    }
docs: Set or unset the uuid of the manual baseline analysis by updating the manual_baseline_analysis_uuid column, if:
  
  - the specified uuid exists
  - and the specified uuid corresponds to a long-living branch (including the main branch)
  
  @return the number of rows that were updated