Zend\Diactoros\ServerRequestFactory::normalizeServer PHP Method

    public static function normalizeServer(array $server)
    {
        // This seems to be the only way to get the Authorization header on Apache
        $apacheRequestHeaders = self::$apacheRequestHeaders;
        if (isset($server['HTTP_AUTHORIZATION']) || !is_callable($apacheRequestHeaders)) {
            return $server;
        }
        $apacheRequestHeaders = $apacheRequestHeaders();
        if (isset($apacheRequestHeaders['Authorization'])) {
            $server['HTTP_AUTHORIZATION'] = $apacheRequestHeaders['Authorization'];
            return $server;
        }
        if (isset($apacheRequestHeaders['authorization'])) {
            $server['HTTP_AUTHORIZATION'] = $apacheRequestHeaders['authorization'];
            return $server;
        }
        return $server;
    }

 public static function fromGlobals(array $server = null, array $query = null, array $body = null, array $cookies = null, array $files = null)
 {
     $server = parent::normalizeServer($server);
     $files = parent::normalizeFiles($files);
     $headers = parent::marshalHeaders($server);
     return new ServerRequest($server, $files, parent::marshalUriFromServer($server, $headers), parent::get('REQUEST_METHOD', $server, 'GET'), 'php://input', $headers, $cookies, $query, $body, self::marshalProtocolVersion($server));
 }