How to test angularJs http request jsonp - angularjs

Question

So, i am trying to follow this tutorial while trying to create some unit tests along the way.
Well i am stuck at trying to test the $http request to the ergast developer api. As u can see in the tutorial the $http request is made to the service ergastAPIservice
angular.module('F1FeederApp.services', []).
factory('ergastAPIservice', function($http) {
var ergastAPI = {};
ergastAPI.getDrivers = function() {
return $http({
method: 'JSONP',
url: 'http://ergast.com/api/f1/2013/driverStandings.json?callback=JSON_CALLBACK'
});
}
return ergastAPI;
});
Which is then used in the controller:
angular.module('F1FeederApp.controllers', []).
controller('driversController', function($scope, ergastAPIservice) {
$scope.nameFilter = null;
$scope.driversList = [];
ergastAPIservice.getDrivers().success(function (response) {
$scope.driversList = response.MRData.StandingsTable.StandingsLists[0].DriverStandings;
});
});
How would i go about testing this (the service). I have started up something like this:
describe('F1FeederApp services', function() {
describe('ergastAPIservice', function(){
var scope, ctrl, $httpBackend;
beforeEach(module('F1FeederApp'));
beforeEach(inject(function(_$httpBackend_, $rootScope, $controller) {
scope = $rootScope.$new();
ctrl = $controller('driversController', {$scope: scope});
$httpBackend = _$httpBackend_;
$httpBackend.whenJSONP("
http://ergast.com/api/f1/2013/driverStandings.json?callback=JSON_CALLBACK").
respond(WHAT SHOULD GO HERE);
}));
it("should get ???", function () {
$httpBackend.flush();
expect(WHAT SHOULD GO HERE).toEqual('foo');
});
});});
Like i said stuck,getting this to work, i thought that what ever you put in the respond should be what u expect in your test, that it doesn't have anything to do with the actual mocked $http request...or am i getting this all wrong
Any tips and/or pointing me in the right direction would be very appreciated,
Cheers!