public function insertToken(string $lockTo = '', bool $echo = true): string
    {
        $token_array = $this->getTokenArray($lockTo);
        $ret = \implode(
            \array_map(
                function(string $key, string $value): string {
                    return "<!--\n-->".
                        "<input type=\"hidden\"" .
                        " name=\"" . $key . "\"" .
                        " value=\"" . self::noHTML($value) . "\"" .
                        " />";
                },
                \array_keys($token_array),
                $token_array
            )
        );
        if ($echo) {
            echo $ret;
            return '';
        }
        return $ret;
    }