static public function clear_backup_dir($backupid, \core\progress\base $progress = null) {
        $backupiddir = make_backup_temp_directory($backupid, false);
        if (!self::delete_dir_contents($backupiddir, '', $progress)) {
            throw new backup_helper_exception('cannot_empty_backup_temp_dir');
        }
        return true;
    }
static public function clear_backup_dir($backupid, \core\progress\base $progress = null) {
        $backupiddir = make_backup_temp_directory($backupid, false);
        if (!self::delete_dir_contents($backupiddir, '', $progress)) {
            throw new backup_helper_exception('cannot_empty_backup_temp_dir');
        }
        return true;
    }
static public function clear_backup_dir ( $ backupid , \ core \ progress \ base $ progress = null ) { $ backupiddir = make_backup_temp_directory ( $ backupid , false ) ; if ( ! self :: delete_dir_contents ( $ backupiddir , '' , $ progress ) ) { throw new backup_helper_exception ( 'cannot_empty_backup_temp_dir' ) ; } return true ; }
Given one backupid, ensure its temp dir is completely empty

If supplied, progress object should be ready to receive indeterminate
progress reports.

@param string $backupid Backup id
@param \core\progress\base $progress Optional progress reporting object
Given one backupid ensure its temp dir is completely empty