1. @override
Future<RequestOrResponse> processRequest(Request req)

Overridden by subclasses to modify or respond to an incoming request.

Subclasses override this method to provide their specific handling of a request. A RequestController should either modify or respond to the request. For concrete subclasses of RequestController - like HTTPController - this method has already been implemented.

RequestControllers should return a Response from this method if they responded to the request. If a RequestController does not respond to the request, but instead modifies it, this method must return the same Request.

Source 

@override
Future<RequestOrResponse> processRequest(Request req) async {
  var header = req.innerRequest.headers.value(HttpHeaders.AUTHORIZATION);
  if (header == null) {
    return new Response.unauthorized();
  }

  switch (strategy) {
    case AuthStrategy.bearer: return _processBearerHeader(req, header);
    case AuthStrategy.basic: return _processBasicHeader(req, header);
    default: return new Response.serverError();
  }
}