wp_render_elements_class_name( string $block_content, array $block ): string

246function wp_render_elements_class_name( $block_content, $block ) {247	$class_string = $block['attrs']['className'] ?? '';248	preg_match( '/\bwp-elements-\S+\b/', $class_string, $matches );249 250	if ( empty( $matches ) ) {251		return $block_content;252	}253 254	$tags = new WP_HTML_Tag_Processor( $block_content );255 256	if ( $tags->next_tag() ) {257		$tags->add_class( $matches[0] );258	}259 260	return $tags->get_updated_html();261}