public function add_worksheet($name = '') {
        $ws = new MoodleODSWorksheet($name, $this->worksheets);
        $this->worksheets[] = $ws;
        return $ws;
    }
public function add_worksheet($name = '') {
        $ws = new MoodleODSWorksheet($name, $this->worksheets);
        $this->worksheets[] = $ws;
        return $ws;
    }
public function add_worksheet ( $ name = '' ) { $ ws = new MoodleODSWorksheet ( $ name , $ this -> worksheets ) ; $ this -> worksheets [ ] = $ ws ; return $ ws ; }
Create one Moodle Worksheet.

@param string $name Name of the sheet
@return MoodleODSWorksheet
Create one Moodle Worksheet .