private Optional <RecordT> ConvertVisualIdxToPhysicalItem(int tbodyRowIdx)
{
var visualIdx = RelativeVisualIdxToAbsoluteVisualIdx(tbodyRowIdx);
if (GetGroupForTrailerOrNull(visualIdx) != null)
{
return(Optional <RecordT> .CreateNone());
}
var groupRecordsCnt = GetExtraGroupRowsCount(visualIdx);
return(Optional <RecordT> .CreateSome(_model.Items[visualIdx - groupRecordsCnt]));
}