HttpResponse::copyHeadersTo

public function copyHeadersTo(HttpResponse $response): HttpResponse
{
	$httpHeaders = $response->getHeaders();

	foreach ($this->getHeaders() as $headerName => $values)
	{
		if ($this->shouldIgnoreHeaderToClone($headerName))
		{
			continue;
		}

		if ($httpHeaders->get($headerName))
		{
			continue;
		}

		$httpHeaders->add($headerName, $values);
	}

	foreach ($this->getCookies() as $cookie)
	{
		$response->addCookie($cookie, false);
	}

	return $response;
}