insertRowPageBreak method
Inserts a manual page break above rowIndex (0-based) so that row begins a
new printed page. Indices <= 0 are ignored; there is no page above the
first row.
Implementation
void insertRowPageBreak(int rowIndex) {
if (rowIndex <= 0) return;
if (_rowBreaks.add(rowIndex)) _pageBreaksChanged = true;
}