protected function addColumns($columns)
    {
        $model = $this->models->first();

        if ($columns) {
            foreach ($columns as $key => $field) {
                if (is_numeric($key)) {
                    // Simple non-keyed array passed.
                    $new_column = Column::create($field);
                } else {
                    // Key also matters, apparently
                    $new_column = Column::create($key, $field);
                }

                $new_column->setOptionsFromModel($model);

                $this->columns[] = $new_column;
            }
        }
    }