toJson method
Implementation
core.Map<core.String, core.dynamic> toJson() => {
if (endColumnIndex != null) 'endColumnIndex': endColumnIndex!,
if (endRowIndex != null) 'endRowIndex': endRowIndex!,
if (sheetId != null) 'sheetId': sheetId!,
if (startColumnIndex != null) 'startColumnIndex': startColumnIndex!,
if (startRowIndex != null) 'startRowIndex': startRowIndex!,
};