code: private void setLastCompleted(long lastCompleted) {
      if (!log.isOpen())
        return;
  
      this.lastCompleted = Math.max(this.lastCompleted, lastCompleted);
  
      // Update the log compaction minor index.
      log.compactor().minorIndex(this.lastCompleted);
  
      completeSnapshot();
    }
docs: Updates the last completed event index based on a commit at the given index.