c-template-functions.php/#L2039-L2074
	 *
	 * @param number $product_per_page Products per page.
	 * @return array Products ids.
	 */
	private function get_related_products_ids( $product_per_page = 5 ) {
		global $post;

		$product = wc_get_product( $post->ID );

		$related_products = array_filter( array_map( 'wc_get_product', wc_get_related_products( $product->get_id(), $product_per_page, $product->get_upsell_ids() ) ), 'wc_products_array_filter_visible' );
		$related_products = wc_products_array_orderby( $related_products, 'rand', 'desc' );

		$related_product_ids = array_map(
			function( $product ) {
				return $product->get_id();
			},
			$related_products
		);

		return $related_product_ids;
	}

}
<br />
<b>Fatal error</b>:  Uncaught Error: Class 'Automattic\WooCommerce\Blocks\BlockTypes\RelatedProducts' not found in /home/htzanetatos/public_html/wp-content/plugins/woocommerce/src/Blocks/BlockTypesController.php:117
Stack trace:
#0 /home/htzanetatos/public_html/wp-includes/class-wp-hook.php(324): Automattic\WooCommerce\Blocks\BlockTypesController-&gt;register_blocks('')
#1 /home/htzanetatos/public_html/wp-includes/class-wp-hook.php(348): WP_Hook-&gt;apply_filters(NULL, Array)
#2 /home/htzanetatos/public_html/wp-includes/plugin.php(517): WP_Hook-&gt;do_action(Array)
#3 /home/htzanetatos/public_html/wp-settings.php(727): do_action('init')
#4 /home/htzanetatos/public_html/wp-config.php(83): require_once('/home/htzanetat...')
#5 /home/htzanetatos/public_html/wp-load.php(50): require_once('/home/htzanetat...')
#6 /home/htzanetatos/public_html/wp-blog-header.php(13): require_once('/home/htzanetat...')
#7 /home/htzanetatos/public_html/index.php(17): require('/home/htzanetat...')
#8 {main}
  thrown in <b>/home/htzanetatos/public_html/wp-content/plugins/woocommerce/src/Blocks/BlockTypesController.php</b> on line <b>117</b><br />