code: func (merger *MatchMerger) GetMergedBlocks() (sorted BlockSpanList) {
  	merger.wait.Wait()
  	var smallestKey uint = 0
  	m := merger.startEndBlockMap
  
  	m.AscendGreaterOrEqual(m.Min(), func(item llrb.Item) bool {
  		switch block := item.(type) {
  		case BlockSpanStart:
  			sorted = append(sorted, BlockSpan(block))
  			smallestKey = block.StartBlock + 1
  		}
  		return true
  	})
  
  	sort.Sort(sorted)
  	return
  }
docs: // Sorted list of blocks, based on StartBlock