code: func (b *Bitmap) Size() int {
  	numbytes := 0
  	citer, _ := b.Containers.Iterator(0)
  	for citer.Next() {
  		_, c := citer.Value()
  		numbytes += c.size()
  
  	}
  	return numbytes
  }
docs: // Size returns the number of bytes required for the bitmap.