54      * @param string[] $headers
56     private function getHeaders(array $headers): string  argument
59         foreach ($headers as $key => $value) {
103         [$body, $headers] = $this->createElement(
110         $stream->addStream(Utils::streamFor($this->getHeaders($headers)));
116      * @param string[] $headers
120 …tion createElement(string $name, StreamInterface $stream, ?string $filename, array $headers): array  argument
123         $disposition = self::getHeader($headers, 'content-disposition');
125             $headers['Content-Disposition'] = ($filename === '0' || $filename)
135         $length = self::getHeader($headers, 'content-length');
138                 $headers['Content-Length'] = (string) $length;
143         $type = self::getHeader($headers, 'content-type');
145 …        $headers['Content-Type'] = MimeType::fromFilename($filename) ?? 'application/octet-stream';
148         return [$stream, $headers];
152      * @param string[] $headers
154     private static function getHeader(array $headers, string $key): ?string  argument
157         foreach ($headers as $k => $v) {