public function getConcatMessage($field = null, string $sep = ' ', bool $punctuate = true): string {
        $sentence = $this->translate('%s.');

        $errors = $field === null ? $this->getRawErrors() : ($this->errors[$field] ?? []);

        // Generate the message by concatenating all of the errors together.
        $messages = [];
        foreach ($errors as $field => $error) {
            $message = $this->formatErrorMessage($error + ['field' => $field]);
            if ($punctuate && preg_match('`\PP$`u', $message)) {
                $message = sprintf($sentence, $message);
            }
            $messages[] = $message;
        }
        return implode($sep, $messages);
    }