RunnerRequestCallback extends RequestCallback<T> { @Override public void onSuccess(T result) { successCallback.onSuccess(result); } RunnerRequestCallback(@NotNull NotificationManager notificationManager,
                                 @Nullable Unmarshallable<T> unmarshallable,
                                 @NotNull SuccessCallback<T> successCallback,
                                 @Nullable FailureCallback failureCallback); @Override void onSuccess(T result); @Override void onFailure(Throwable exception);  }
@Test public void successCallBackShouldBeCalled() throws Exception { requestCallback.onSuccess(result); verify(successCallback).onSuccess(result); }