public function append($line, $newline = true, $indentOffset = 0)
    {
        $line = trim($line);
        if (strlen($line) > 0) {
            parent::append(
                self::COMMENT_LINE_PREFIX . ' ' . $line, $newline, $indentOffset
            );
        } else {
            parent::append(
                self::COMMENT_LINE_PREFIX, $newline, $indentOffset
            );
        }
        return $this;
    }