protected function backupFileName($extension, $timestamp = null)
    {
        if (is_null($timestamp)) {
            $timestamp = $this->time;
        }
        return $timestamp . '_' . date('Y_m_d_H_i_s', $timestamp) . $extension;
    }
protected function backupFileName($extension, $timestamp = null)
    {
        if (is_null($timestamp)) {
            $timestamp = $this->time;
        }
        return $timestamp . '_' . date('Y_m_d_H_i_s', $timestamp) . $extension;
    }
protected function backupFileName ( $ extension , $ timestamp = null ) { if ( is_null ( $ timestamp ) ) { $ timestamp = $ this -> time ; } return $ timestamp . '_' . date ( 'Y_m_d_H_i_s' , $ timestamp ) . $ extension ; }
Generate a backup filename based on the given time.

@param string $extension
The extension to append to the filename. Must include leading dot.
@param int|null $timestamp
The timestamp to generate the backup name from. Defaults to the request
time.

@return string
The generated filename.
Generate a backup filename based on the given time .