private Cell<T> _insertCellBefore() {
Cell<T> newCell = new Cell<T>(parent, prevCell, this);
if (prevCell == null) {
parent.firstCell = newCell;
} else {
prevCell.nextCell = newCell;
}
prevCell = newCell;
return newCell;
}
public Cell<T> insertCellBefore() {
// Make sure first cell is empty
if (parent.firstCell.isFilled()) {
parent.parent.addFirstColumn();
}
_insertCellBefore();
// Trim beginning of row
parent.firstCell.getNextCell().prevCell = null;
parent.firstCell = parent.firstCell.getNextCell();
return getPrevCell();
}