code: private void releaseSealedSegments() throws ReaderNotInReaderGroupException {
          for (Iterator<Segment> iterator = sealedSegments.iterator(); iterator.hasNext();) {
              Segment oldSegment = iterator.next();
              if (groupState.handleEndOfSegment(oldSegment)) {
                  iterator.remove();
              } else {
                  break;
              }
          }    
      }
docs: Releases all sealed segments, unless there is a checkpoint pending for this reader.