### Question:
MultiCallbacks extends Callbacks { @Override public void onFailure() { for (Callbacks callback : callbacks) { callback.onFailure(); } } MultiCallbacks(Callbacks... callbacks); @Override void onStart(); @Override void onSuccess(); @Override void onFailure(); @Override void onComplete();  }### Answer:
@Test public void onFailure_shouldCallThroughToAllProvidedCallbacks() throws Exception { multiCallbacks.onFailure(); assertThat(testCallbacks0.failureWasCalled, equalTo(true)); assertThat(testCallbacks1.failureWasCalled, equalTo(true)); }