code: func (sba *sparseBitArray) ToNums() []uint64 {
  	if len(sba.indices) == 0 {
  		return nil
  	}
  
  	diff := uint64(len(sba.indices)) * s
  	nums := make([]uint64, 0, diff/4)
  
  	for i, offset := range sba.indices {
  		sba.blocks[i].toNums(offset*s, &nums)
  	}
  
  	return nums
  }
docs: // ToNums converts this sparse bitarray to a list of numbers contained
  // within it.