Dim i As Int
Dim theSheet As PoiSheet = ...
Dim joTheSheet As JavaObject = theSheet
Dim theSheetWriter As XLSheetWriter = ...
Dim theSheetLastRow1 As Int = theSheet.LastRowNumber + 1 ' One-based index of the last row in the sheet
Dim theSheetLastCol0 As Int = theSheet.GetRow(0).Cells.Size - 1 '...