KoaOAuthServer.prototype.authenticate lack of response

KoaOAuthServer.prototype.authenticate = function() {
  var server = this.server;

  return function *(next) {
    var request = new Request(this.request);
    var response = new Response(this.response);

```
try {
  this.state.oauth = {
    token: yield server.authenticate(request,response)
  };
} catch (e) {
  return handleError.call(this, e);
}

yield* next;
```

  };
};
