code: func NewAllocationMap(max int, rangeSpec string) *AllocationBitmap {
  	a := AllocationBitmap{
  		strategy: randomScanStrategy{
  			rand: rand.New(rand.NewSource(time.Now().UnixNano())),
  		},
  		allocated: big.NewInt(0),
  		count:     0,
  		max:       max,
  		rangeSpec: rangeSpec,
  	}
  	return &a
  }
docs: // NewAllocationMap creates an allocation bitmap using the random scan strategy.