@Override
    @Transactional
    public void deleteProduct(Integer id) {
        this.productRepository.deleteById(id);
    }
@Test
    void deleteProduct_DeletesProduct() {
        // given
        var productId = 1;

        // when
        this.service.deleteProduct(productId);

        // then
        verify(this.productRepository).deleteById(productId);
        verifyNoMoreInteractions(this.productRepository);
    }