### Question:
CustomerService { public List<Customer> getCustomers() { log.debug("Get all customers"); return customerRepository.getCustomers(); }  List<Customer> getCustomers(); Customer getByEmail(String email); void store(Customer newCustomer);  }### Answer:
@Test public void getCustomers() { List<Customer> customers = customerService.getCustomers(); Assertions.assertThat(customers).hasSize(0); Mockito.verify(customerRepository).getCustomers(); }