private function getTrimmedJson(callable $inner, int $limit, string $error): array
    {
        $gcmInner = $inner($this->text);
        $gcmInnerJson = json_encode($gcmInner, JSON_UNESCAPED_UNICODE);
        if (($gcmInnerJsonLength = \strlen($gcmInnerJson)) > $limit) {
            $cut = $gcmInnerJsonLength - $limit;
            //Note that strlen returns the byte length of the string
            if ($this->text && ($textLength = \strlen($this->text)) > $cut && $this->allowTrimming) {
                $gcmInner = $inner(mb_strcut($this->text, 0, $textLength - $cut - 3, 'utf8').'...');
            } else {
                throw new MessageTooLongException("$error $gcmInnerJson");
            }
        }

        return $gcmInner;
    }