public function lastColumn()
    {
        static $last;

        if (!$last) {
            $columns = $this->columns();
            end($columns);
            $last = key($columns) + 1;
        }

        return $last;
    }
public function lastColumn()
    {
        static $last;

        if (!$last) {
            $columns = $this->columns();
            end($columns);
            $last = key($columns) + 1;
        }

        return $last;
    }
{@inheritDoc}