public function get_columns() {

		$columns = array(
			'product'      => __( 'Product', 'woocommerce' ),
			'parent'       => __( 'Parent', 'woocommerce' ),
			'stock_level'  => __( 'Units in stock', 'woocommerce' ),
			'stock_status' => __( 'Stock status', 'woocommerce' ),
			'wc_actions'   => __( 'Actions', 'woocommerce' ),
		);

		return $columns;
	}