1. override
Future<Response> handle(Request request)

Source 

@override Future<Response> handle(Request request) async {
  try {
    if (await context.container.resolve(condition)) {
      return await pipeline(request);
    } else {
      return await super.handle(request);
    }
  } on NoResponseFromPipelineException {
    return await super.handle(request);
  }
}