  @Test
  public void states_should_observeInitialState() {

    //GIVEN
    Store<Integer> store = new Store<>(0);
    TestSubscriber<Integer> testSubscriber = new TestSubscriber<>();

    //WHEN
    states(store).subscribe(testSubscriber);

    //THEN
    testSubscriber.assertNoTerminalEvent();
    testSubscriber.assertValue(0);
  }