selectRangeValues method
returns 2-D dynamic List of the sheet elements in that range.
Implementation
List<List<dynamic>?> selectRangeValues(CellIndex start, {CellIndex? end}) {
var list = (end == null
? selectRange(start)
: selectRange(start, end: end));
return list
.map((List<Data?>? e) => e?.map((e1) => e1?.value).toList())
.toList();
}