docs: static void mapExplicitly() {
      Order order = createOrder();
      ModelMapper modelMapper = new ModelMapper();
      modelMapper.addMappings(new PropertyMap<Order, OrderDTO>() {
        @Override
        protected void configure() {
          map().setBillingStreet(source.getBillingAddress().getStreet());
          map(source.billingAddress.getCity(), destination.billingCity);
        }
      });
  
      OrderDTO orderDTO = modelMapper.map(order, OrderDTO.class);
      assertOrdersEqual(order, orderDTO);
    }