func (rh *RocksDBHandler) copySlice(slice *rocks.Slice, toFree bool) []byte {
data := make([]byte, slice.Size())
copy(data, slice.Data())
if toFree {
slice.Free()
}
return data
}
func makeSlice(s *rocks.Slice) []byte {
slice := make([]byte, s.Size())
copy(slice, s.Data())
s.Free()
return slice
}