CFile::close PHP Method

    private function close()
    {
        if ($this->_handle !== null) {
            fclose($this->_handle);
            $this->_handle = null;
        }
    }

 private static function writeCSVRecords($file, $request_id, $records)
 {
     $f = new CFile($file);
     $f->open('a');
     foreach ($records as $fields) {
         $f->write($request_id . self::csv_fields_delimiter);
         $f->write(implode(self::csv_fields_delimiter, $fields));
         $f->write(self::csv_lines_delimiter);
     }
     $f->close();
 }