public function withoutHeader($header)
    {
        $header = strtolower($header);
        $response = clone $this;
        $response->headers = array_filter($this->headers, function ($key) use ($header) {
            return $key !== $header;
        }, ARRAY_FILTER_USE_KEY);

        return $response;
    }
public function withoutHeader($header)
    {
        $header = strtolower($header);
        $response = clone $this;
        $response->headers = array_filter($this->headers, function ($key) use ($header) {
            return $key !== $header;
        }, ARRAY_FILTER_USE_KEY);

        return $response;
    }
{@inheritdoc}