/** @test */
 function it_should_allow_extending_a_service_definition_more_than_once()
 {
     $resolver = new Resolver();
     $app = new Slim();
     $app->container->singleton('service', function () {
         return new stdClass();
     });
     $resolver->extend($app, 'service', function (stdClass $service) {
         $service->first = true;
         return $service;
     });
     $resolver->extend($app, 'service', function (stdClass $service) {
         $service->second = true;
         return $service;
     });
     $service = $app->container->get('service');
     $this->assertObjectHasAttribute('first', $service);
     $this->assertTrue($service->first);
     $this->assertObjectHasAttribute('second', $service);
     $this->assertTrue($service->second);
 }