public function _post_gallery( $output, $attr, $instance ) {
		$post = get_post();

		if ( ! empty( $attr['ids'] ) ) {
			if ( empty( $attr['orderby'] ) ) {
				$attr['orderby'] = 'post__in';
			}
			$attr['include'] = $attr['ids'];
		}

		$atts = shortcode_atts( [
			'id'      => $post ? $post->ID : 0,
			'link'    => '',
			'size'    => 'thumbnail',
			'columns' => 3,
			'order'   => 'ASC',
			'orderby' => 'menu_order ID',
			'include' => '',
		], $attr );

		$pot_id = intval( $atts['id'] );

		if ( ! empty( $atts['include'] ) ) {
			$attachments = get_posts( array(
				'include'        => $atts['include'],
				'post_status'    => 'inherit',
				'post_type'      => 'attachment',
				'post_mime_type' => 'image',
				'order'          => $atts['order'],
				'orderby'        => $atts['orderby'],
			) );
		} else {
			$attachments = get_children( array(
				'post_parent'    => $pot_id,
				'post_status'    => 'inherit',
				'post_type'      => 'attachment',
				'post_mime_type' => 'image',
				'order'          => $atts['order'],
				'orderby'        => $atts['orderby'],
			) );
		}

		if ( empty( $attachments ) ) {
			return '';
		}

		if ( is_feed() ) {
			return $this->_render( 'feed', array(
				'attachments' => $attachments,
			) );
		}

		return $this->_render( 'pure-css-gallery', array(
			'attachments' => array_values( $attachments ),
			'atts'        => $atts,
		) );
	}