private function parseRequestHeaders($raw_headers)
{
$request_headers = new CaseInsensitiveArray();
list($first_line, $headers) = $this->parseHeaders($raw_headers);
$request_headers['Request-Line'] = $first_line;
foreach ($headers as $key => $value) {
$request_headers[$key] = $value;
}
return $request_headers;
}