code: @Test public void shouldCollectCorrectNumberOfResourcesByType(){
    final Group group=new Group("group");
    group.addResource(Resource.create("1.js"));
    group.addResource(Resource.create("2.js"));
    group.addResource(Resource.create("3.js"));
    group.addResource(Resource.create("4.js"));
    group.addResource(Resource.create("5.js"));
    group.addResource(Resource.create("6.js"));
    group.addResource(Resource.create("1.css"));
    Assert.assertEquals(6,group.collectResourcesOfType(ResourceType.JS).getResources().size());
    Assert.assertEquals(1,group.collectResourcesOfType(ResourceType.CSS).getResources().size());
  }
  