private function getAllHeaders()
    {
        $headers = [];
        foreach ($_SERVER as $name => $value) {
            if (substr($name, 0, 5) == 'HTTP_') {
                $name = str_replace(' ', '-', ucwords(strtolower(str_replace('_', ' ', substr($name, 5)))));
                $headers[$name] = $value;
            } else {
                if ($name == "CONTENT_TYPE") {
                    $headers["Content-Type"] = $value;
                } else {
                    if ($name == "CONTENT_LENGTH") {
                        $headers["Content-Length"] = $value;
                    }
                }
            }
        }

        return $headers;
    }