void endCell() {
        if (needSuppressEnd()) {
            return;
        }
        switch (state) {
            case IN_CELL_IN_ROW_GROUP:
                state = State.IN_ROW_IN_ROW_GROUP;
                break;
            case IN_CELL_IN_IMPLICIT_ROW_GROUP:
                state = State.IN_ROW_IN_IMPLICIT_ROW_GROUP;
                break;
            default:
                throw new IllegalStateException("Bug!");
        }
    }
Constructor.
@param owner reference back to the checker
src/nu/validator/checker/table/Table.java