@Override
    public Set<StoreBuilder<?>> stores() {
        return transformerSupplier.stores();
    }
@Test
    public void shouldCallStoresOfAdaptedTransformerSupplier() {
        when(transformerSupplier.stores()).thenReturn(stores);

        final TransformerSupplierAdapter<String, String, Integer, Integer> adapter =
            new TransformerSupplierAdapter<>(transformerSupplier);
        adapter.stores();
    }