nation_arrow( $block, $is_next ) {
	$arrow_map = array(
		'none'    => '',
		'arrow'   => array(
			'next'     => '→',
			'previous' => '←',
		),
		'chevron' => array(
			'next'     => '»',
			'previous' => '«',
		),
	);
	if ( ! empty( $block->context['paginationArrow'] ) && array_key_exists( $block->context['paginationArrow'], $arrow_map ) && ! empty( $arrow_map[ $block->context['paginationArrow'] ] ) ) {
		$pagination_type = $is_next ? 'next' : 'previous';
		$arrow_attribute = $block->context['paginationArrow'];
		$arrow           = $arrow_map[ $block->context['paginationArrow'] ][ $pagination_type ];
		$arrow_classes   = "wp-block-query-pagination-$pagination_type-arrow is-arrow-$arrow_attribute";
		return "<span class='$arrow_classes' aria-hidden='true'>$arrow</span>";
	}
	return null;
}

/**
 * Helper function that constructs a comment query vars array from the passed
 * block properties.
 *
 * It's used with the Comment Query Loop inner blocks.
 *
 * @since 6.0.0
 *
 * @param WP_Block $block Block instance.
 * @return array Returns the comment query parameters to use with the
 *               WP_Comment_Query constructor.
 */
function build_comment_query_vars_from_block( $block ) {

	$comment_args = array(
		'orderby'       => 'comment_date_gmt',
		'order'         => 'ASC',
		'status'        => 'approve',
		'no_found_rows' => false,
	);

	if ( is_user_logged_in() ) {
		$comment_args['include_unapproved'] = array( get_current_user_id() );
	} else {
		$unapproved_email = wp_get_unapproved_comment_author_email();

		if ( $unapproved_email ) {
			$comment_args['include_unapproved'] = array( $unapproved_email );
		}
	}

	if ( ! empty( $block->context['postId'] ) ) {
		$comment_args['post_id'] = (int) $block->context['postId'];
	}

	if ( get_option( 'thread_comments' ) ) {
		$comment_args['hierarchical'] = 'threaded';
	} else {
		$comment_args['hierarchical'] = false;
	}

	if ( get_option( 'page_comments' ) === '1' || get_option( 'page_comments' ) === true ) {
		$per_page     = get_option( 'comments_per_page' );
		$default_page = get_option( 'default_comments_page' );
		if ( $per_page > 0 ) {
			$comment_args['number'] = $per_page;

			$page = (int) get_query_var( 'cpage' );
			if ( $page ) {
				$comment_args['paged'] = $page;
			} elseif ( 'oldest' === $default_page ) {
				$comment_args['paged'] = 1;
			} elseif ( 'newest' === $default_page ) {
				$max_num_pages = (int) ( new WP_Comment_Query( $comment_args ) )->max_num_pages;
				if ( 0 !== $max_num_pages ) {
					$comment_args['paged'] = $max_num_pages;
				}
			}
		}
	}

	return $comment_args;
}

/**
 * Helper function that returns the proper pagination arrow HTML for
 * `CommentsPaginationNext` and `CommentsPaginationPrevious` blocks based on the
 * provided `paginationArrow` from `CommentsPagination` context.
 *
 * It's used in CommentsPaginationNext and CommentsPaginationPrevious blocks.
 *
 * @since 6.0.0
 *
 * @param WP_Block $block           Block instance.
 * @param string   $pagination_type Optional. Type of the arrow we will be rendering.
 *                                  Accepts 'next' or 'previous'. Default 'next'.
 * @return string|null The pagination arrow HTML or null if there is none.
 */
function get_comments_pagination_arrow( $block, $pagination_type = 'next' ) {
	$arrow_map = array(
		'none'    => '',
		'arrow'   => array(
			'next'     => '→',
			'previous' => '←',
		),
		'chevron' => array(
			'next'     => '»',
			'previous' => '«',
		),
	);
	if ( ! empty( $block->context['comments/paginationArrow'] ) && ! empty( $arrow_map[ $block->context['comments/paginationArrow'] ][ $pagination_type ] ) ) {
		$arrow_attribute = $block->context['comments/paginationArrow'];
		$arrow           = $arrow_map[ $block->context['comments/paginationArrow'] ][ $pagination_type ];
		$arrow_classes   = "wp-block-comments-pagination-$pagination_type-arrow is-arrow-$arrow_attribute";
		return "<span class='$arrow_classes' aria-hidden='true'>$arrow</span>";
	}
	return null;
}

/**
 * Strips all HTML from the content of footnotes, and sanitizes the ID.
 *
 * This function expects slashed data on the footnotes content.
 *
 * @access private
 * @since 6.3.2
 *
 * @param string $footnotes JSON-encoded string of an array containing the content and ID of each footnote.
 * @return string Filtered content without any HTML on the footnote content and with the sanitized ID.
 */
function _wp_filter_post_meta_footnotes( $footnotes ) {
	$footnotes_decoded = json_decode( $footnotes, true );
	if ( ! is_array( $footnotes_decoded ) ) {
		return '';
	}
	$footnotes_sanitized = array();
	foreach ( $footnotes_decoded as $footnote ) {
		if ( ! empty( $footnote['content'] ) && ! empty( $footnote['id'] ) ) {
			$footnotes_sanitized[] = array(
				'id'      => sanitize_key( $footnote['id'] ),
				'content' => wp_unslash( wp_filter_post_kses( wp_slash( $footnote['content'] ) ) ),
			);
		}
	}
	return wp_json_encode( $footnotes_sanitized );
}

/**
 * Adds the filters for footnotes meta field.
 *
 * @access private
 * @since 6.3.2
 */
function _wp_footnotes_kses_init_filters() {
	add_filter( 'sanitize_post_meta_footnotes', '_wp_filter_post_meta_footnotes' );
}

/**
 * Removes the filters for footnotes meta field.
 *
 * @access private
 * @since 6.3.2
 */
function _wp_footnotes_remove_filters() {
	remove_filter( 'sanitize_post_meta_footnotes', '_wp_filter_post_meta_footnotes' );
}

/**
 * Registers the filter of footnotes meta field if the user does not have `unfiltered_html` capability.
 *
 * @access private
 * @since 6.3.2
 */
function _wp_footnotes_kses_init() {
	_wp_footnotes_remove_filters();
	if ( ! current_user_can( 'unfiltered_html' ) ) {
		_wp_footnotes_kses_init_filters();
	}
}

/**
 * Initializes the filters for footnotes meta field when imported data should be filtered.
 *
 * This filter is the last one being executed on {@see 'force_filtered_html_on_import'}.
 * If the input of the filter is true, it means we are in an import situation and should
 * enable kses, independently of the user capabilities. So in that case we call
 * _wp_footnotes_kses_init_filters().
 *
 * @access private
 * @since 6.3.2
 *
 * @param string $arg Input argument of the filter.
 * @return string Input argument of the filter.
 */
function _wp_footnotes_force_filtered_html_on_import_filter( $arg ) {
	// If `force_filtered_html_on_import` is true, we need to init the global styles kses filters.
	if ( $arg ) {
		_wp_footnotes_kses_init_filters();
	}
	return $arg;
}
<br />
<b>Fatal error</b>:  Uncaught Error: Call to undefined function filter_block_content() in /home/ocb/public_html/wp-includes/formatting.php:5200
Stack trace:
#0 /home/ocb/public_html/wp-includes/class-wp-hook.php(324): wp_pre_kses_block_attributes('', Array, Array)
#1 /home/ocb/public_html/wp-includes/plugin.php(205): WP_Hook-&gt;apply_filters('', Array)
#2 /home/ocb/public_html/wp-includes/kses.php(946): apply_filters('pre_kses', '', Array, Array)
#3 /home/ocb/public_html/wp-includes/kses.php(754): wp_kses_hook('', Array, Array)
#4 /home/ocb/public_html/wp-admin/includes/plugin.php(188): wp_kses('', Array)
#5 /home/ocb/public_html/wp-admin/includes/plugin.php(114): _get_plugin_data_markup_translate('apus-framework/...', Array, true, true)
#6 /home/ocb/public_html/wp-content/plugins/apus-framework/libs/redux/redux-core/appsero/Client.php(163): get_plugin_data('/home/ocb/publi...')
#7 /home/ocb/public_html/wp-content/plugins/apus-framework/libs/redux/redux-core/appsero/Client.php(92): ReduxAppsero\Client-&gt;set_basename_and_slug()
#8 /h in <b>/home/ocb/public_html/wp-includes/formatting.php</b> on line <b>5200</b><br />