    @Test
    public void testOn(){

        // Arrange
        List<Product> products = new ArrayList<>();
        when(repo.save(any(Product.class)))
                .thenAnswer(i -> {
                    Product prod = i.getArgumentAt(0, Product.class);
                    products.add(prod);
                    return prod;
                });

        // Act
        processor.on(event);

        // Assert
        verify(repo, times(1)).save(any(Product.class));
        verifyNoMoreInteractions(repo);
        Assert.assertEquals(products.get(0).getId(), uuid);
        Assert.assertEquals(products.get(0).getName(), name);

    }