public void collapseRow(int rowNumber) {int startRow = findStartOfRowOutlineGroup(rowNumber);RowRecord rowRecord = getRow(startRow);int nextRowIx = writeHidden(rowRecord, startRow);RowRecord row = getRow(nextRowIx);if (row == null) {row = createRow(nextRowIx);insertRow(row);}row.setColapsed(true);}