@Override
public void merge(boolean across) {
synchronized (_sheet) {
if (_refs != null && !_refs.isEmpty()) {
final Ref ref = _refs.iterator().next();
final RefSheet refSheet = ref.getOwnerSheet();
final RefBook refBook = refSheet.getOwnerBook();
final int tRow = ref.getTopRow();
final int lCol = ref.getLeftCol();
final int bRow = ref.getBottomRow();
final int rCol = ref.getRightCol();
final Worksheet sheet = BookHelper.getSheet(_sheet, refSheet);