public static function save_acf_fields($landing_page_id)
 {
     if (wp_is_post_revision($landing_page_id)) {
         return;
     }
     if (!isset($_POST['post_type']) || $_POST['post_type'] != 'landing-page') {
         return;
     }
     if (defined('DOING_AUTOSAVE') && DOING_AUTOSAVE) {
         return;
     }
     /* save acf settings - uses our future data array - eventually we will migrate all post meta into this data object */
     $fields = isset($_POST['fields']) ? $_POST['fields'] : null;
     $fields = isset($_POST['acf']) ? $_POST['acf'] : $fields;
     if ($fields) {
         $settings = Landing_Pages_Meta::get_settings($landing_page_id);
         $variation_id = isset($_REQUEST['lp-variation-id']) ? $_REQUEST['lp-variation-id'] : '0';
         if (!isset($settings['variations'])) {
             $settings['variations'] = array();
         }
         $settings['variations'][$variation_id]['acf'] = $fields;
         Landing_Pages_Meta::update_settings($landing_page_id, $settings);
     }
 }