code: func (s *SparseRange) ToSlice() (ret []uint32) {
  	for _, itm := range s.Items {
  		switch x := itm.RangeItem.(type) {
  		case *RangeItem_Single:
  			ret = append(ret, x.Single)
  		case *RangeItem_Range:
  			for i := x.Range.Low; i <= x.Range.High; i++ {
  				ret = append(ret, i)
  			}
  		}
  	}
  	return
  }
docs: // ToSlice returns this SparseRange as an expanded slice of uint32s.