@Test
public void testConvertCurrencyOnError() {

    when(rateLoader.loadRate()).thenReturn(Observable.just(2f));
    CurrencyConverterModel model = viewModel.initAndResume();
    model.input.set("abc");
    viewModel.calculate();
    verify(messageManager).showMessage(any(ActivityHolder.class), eq(R.string.conversion_error));
}