@Test
public void requestNativeAd_withNullUrl_shouldFireNativeFailAndNotStartAsyncTask() {

    Robolectric.getUiThreadScheduler().pause();
    subject.requestNativeAd(null);
    verify(mockNetworkListener).onNativeFail(any(NativeErrorCode.class));
    assertThat(wasDownloadTaskExecuted()).isFalse();
}