docs: public final ItemStream findFirstMatchingItemStream(Filter filter) throws MessageStoreException 
      {
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled()) SibTr.entry(this, tc, "findFirstMatchingItemStream", filter);
  
          ItemStream item = (ItemStream) _itemStreams.findFirstMatching(filter);
  
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled()) SibTr.exit(this, tc, "findFirstMatchingItemStream", item);
          return item;
      }