@Test
  public void errorPassedToFailure() {
    RetrofitError exception = RetrofitError.unexpectedError("", null);
    when(callbackRunnable.obtainResponse()).thenThrow(exception);

    callbackRunnable.run();

    verify(executor).execute(any(Runnable.class));
    verify(callback).failure(same(exception));
  }
  @Test
  public void responsePassedToSuccess() {
    ResponseWrapper wrapper = new ResponseWrapper(null, new Object());
    when(callbackRunnable.obtainResponse()).thenReturn(wrapper);

    callbackRunnable.run();

    verify(executor).execute(any(Runnable.class));
    verify(callback).success(same(wrapper.responseBody), same(wrapper.response));
  }