code: func (cms *ConcurrentMergeScheduler) SetMaxMergesAndRoutines(maxMergeCount, maxRoutineCount int) {
  	assert2(maxRoutineCount >= 1, "maxRoutineCount should be at least 1")
  	assert2(maxMergeCount >= 1, "maxMergeCount should be at least 1")
  	assert2(maxRoutineCount <= maxMergeCount, fmt.Sprintf(
  		"maxRoutineCount should be <= maxMergeCount (= %v)", maxMergeCount))
  
  	oldCount := cms.maxRoutineCount
  	cms.maxRoutineCount = maxRoutineCount
  	cms.maxMergeCount = maxMergeCount
  
  	cms.Lock()
  	defer cms.Unlock()
  	for i := oldCount; i < maxRoutineCount; i++ {
  		go cms.worker(i)
  	}
  }
docs: // Sets the maximum number of merge goroutines and simultaneous
  // merges allowed.