Source

File: wp-includes/link-template.php

function get_the_comments_pagination( $args = array() ) {
	$navigation = '';

	// Make sure the nav element has an aria-label attribute: fallback to the screen reader text.
	if ( ! empty( $args['screen_reader_text'] ) && empty( $args['aria_label'] ) ) {
		$args['aria_label'] = $args['screen_reader_text'];
	}

	$args         = wp_parse_args(
		$args,
		array(
			'screen_reader_text' => __( 'Comments navigation' ),
			'aria_label'         => __( 'Comments' ),
			'class'              => 'comments-pagination',
		)
	);
	$args['echo'] = false;

	// Make sure we get a string back. Plain is the next best thing.
	if ( isset( $args['type'] ) && 'array' === $args['type'] ) {
		$args['type'] = 'plain';
	}

	$links = paginate_comments_links( $args );

	if ( $links ) {
		$navigation = _navigation_markup( $links, $args['class'], $args['screen_reader_text'], $args['aria_label'] );
	}

	return $navigation;
}