public static function get_sendback()
 {
     $wp_list_table = new WP_List_Table();
     $pagenum = $wp_list_table->get_pagenum();
     $parent_file = 'admin.php?page=' . $_GET['page'];
     $sendback = remove_query_arg(array('action', 'log'), wp_get_referer());
     if (!$sendback) {
         $sendback = admin_url($parent_file);
     }
     $sendback = add_query_arg('paged', $pagenum, $sendback);
     return $sendback;
 }