render_block_core_tag_cloud

function render_block_core_tag_cloud( $attributes ) {
	$class = isset( $attributes['align'] ) ?
		"wp-block-tag-cloud align{$attributes['align']}" :
		'wp-block-tag-cloud';

	if ( isset( $attributes['className'] ) ) {
		$class .= ' ' . $attributes['className'];
	}

	$args = array(
		'echo'       => false,
		'taxonomy'   => $attributes['taxonomy'],
		'show_count' => $attributes['showTagCounts'],
	);

	$tag_cloud = wp_tag_cloud( $args );

	if ( ! $tag_cloud ) {
		$labels    = get_taxonomy_labels( get_taxonomy( $attributes['taxonomy'] ) );
		$tag_cloud = esc_html(
			sprintf(
				/* translators: %s: taxonomy name */
				__( 'Your site doesn’t have any %s, so there’s nothing to display here at the moment.' ),
				strtolower( $labels->name )
			)
		);
	}

	return sprintf(
		'<p class="%1$s">%2$s</p>',
		esc_attr( $class ),
		$tag_cloud
	);
}