public function get_left_range_row($rows=array(), $colspan=1) {
        global $CFG, $USER;

        if ($this->get_pref('showranges')) {
            $rangerow = new html_table_row();
            $rangerow->attributes['class'] = 'range r'.$this->rowcount++;
            $rangecell = new html_table_cell();
            $rangecell->attributes['class'] = 'header range';
            $rangecell->colspan = $colspan;
            $rangecell->header = true;
            $rangecell->scope = 'row';
            $rangecell->text = $this->get_lang_string('range', 'grades');
            $rangerow->cells[] = $rangecell;
            $rows[] = $rangerow;
        }

        return $rows;
    }