Clear Siteground cache for site or for single page

<?php
/**
 * Clears the SiteGround cache for a specific page or the entire site.
 *
 * This function checks if a valid URL is provided and clears the cache
 * for that specific page. If the URL is invalid or not provided, it clears
 * the cache for the entire site. It relies on the 'sg_cachepress_purge_cache' function
 * provided by SiteGround's caching functionality.
 *
 * Gist Keywords: wordpress, cache, performance, siteground
 *
 * @param string $page_url Optional. The URL of the page to clear the cache for.
 *                         If empty or invalid, the entire cache is cleared.
 * @return void
 * @author Knol Aust
 */
function knolaust_clear_sg_cache($page_url = ''){
    if (function_exists('sg_cachepress_purge_cache')) {
        if (!empty($page_url) && filter_var($page_url, FILTER_VALIDATE_URL)) {
            sg_cachepress_purge_cache($page_url);
        } else {
            sg_cachepress_purge_cache();
        }
    }
}

/** Instructions */
// Usage of knolaust_clear_sg_cache function

// 1. To clear the cache for a specific page:
// Example: knolaust_clear_sg_cache('https://www.example.com/specific-page/');

// 2. To clear the entire site's cache:
// Example: knolaust_clear_sg_cache();

// Notes:
// - The function checks if the provided URL is valid. If the URL is invalid or not provided,
//   the cache for the entire site is cleared.
// - Ensure that the 'sg_cachepress_purge_cache' function is available in your environment.