function setupEnv() {
  firebase  = new MockFirebase("https://something.firebaseio.com");

  container = new Ember.Container();
  store     = Store.create({
    container:    container,
    firebaseRoot: firebase
  });

  Person = Model.extend({
    name: attr(),
    priority: null
  });
  Person.typeKey = "Person";
  container.register("model:person", Person);

  People = ObjectCollection.extend({
    model: Person,
    store: store
  });

  firebase.child("people/123").setWithPriority({name: "Tom"},   10);
  firebase.child("people/234").setWithPriority({name: "Dick"},  20);
  firebase.child("people/456").setWithPriority({name: "Harry"}, 30);
  firebase.flush();
}
  setup: function() {
    firebase  = new MockFirebase("https://something.firebaseio.com");

    container = new Ember.Container();
    store     = Store.create({
      container:    container,
      firebaseRoot: firebase
    });

    Thing = Model.extend({
      name: attr()
    });
    Thing.typeKey = "Thing";

    Other = Model.extend({
      name: attr()
    });
    Thing.typeKey = "Other";

    container.register("model:thing", Thing);
    container.register("model:other", Other);

    firebase.child("things/123").set({name: "One",   type: "thing"});
    firebase.child("things/234").set({name: "Two",   type: "other"});
    firebase.child("things/456").set({name: "Three", type: "thing"});

    var PolyCollection = ObjectCollection.extend({
      store: store,
      firebaseReference: firebase.child("things"),
      modelClassFromSnapshot: function(snapshot) {
        return snapshot.val().type;
      }
    });

    collection = PolyCollection.create();
    collection.listenToFirebase();
    firebase.flush();
  }