### Question:
OrderServiceImpl implements OrderService { public List<String> queryForStationId(List<String> ids, HttpHeaders headers) { HttpEntity requestEntity = new HttpEntity(ids, headers); ResponseEntity<Response<List<String>>> re = restTemplate.exchange( "http: HttpMethod.POST, requestEntity, new ParameterizedTypeReference<Response<List<String>>>() { }); OrderServiceImpl.LOGGER.info("Name List is: {}", re.getBody().toString()); return re.getBody().getData(); }  @Override Response getSoldTickets(Seat seatRequest, HttpHeaders headers); @Override Response findOrderById(UUID id, HttpHeaders headers); @Override Response create(Order order, HttpHeaders headers); @Override Response alterOrder(OrderAlterInfo oai, HttpHeaders headers); @Override Response<ArrayList<Order>> queryOrders(OrderInfo qi, String accountId, HttpHeaders headers); @Override Response queryOrdersForRefresh(OrderInfo qi, String accountId, HttpHeaders headers); List<String> queryForStationId(List<String> ids, HttpHeaders headers); @Override Response saveChanges(Order order, HttpHeaders headers); @Override Response cancelOrder(UUID accountId, UUID orderId, HttpHeaders headers); @Override Response queryAlreadySoldOrders(Date travelDate, String trainNumber, HttpHeaders headers); @Override Response getAllOrders(HttpHeaders headers); @Override Response modifyOrder(String orderId, int status, HttpHeaders headers); @Override Response getOrderPrice(String orderId, HttpHeaders headers); @Override Response payOrder(String orderId, HttpHeaders headers); @Override Response getOrderById(String orderId, HttpHeaders headers); @Override void initOrder(Order order, HttpHeaders headers); @Override Response checkSecurityAboutOrder(Date dateFrom, String accountId, HttpHeaders headers); @Override Response deleteOrder(String orderId, HttpHeaders headers); @Override Response addNewOrder(Order order, HttpHeaders headers); @Override Response updateOrder(Order order, HttpHeaders headers);  }### Answer:
@Test public void testQueryForStationId() { List<String> ids = new ArrayList<>(); HttpEntity requestEntity = new HttpEntity<>(ids, headers); Response<List<String>> response = new Response<>(); ResponseEntity<Response<List<String>>> re = new ResponseEntity<>(response, HttpStatus.OK); Mockito.when(restTemplate.exchange( "http: HttpMethod.POST, requestEntity, new ParameterizedTypeReference<Response<List<String>>>() { })).thenReturn(re); List<String> result = orderServiceImpl.queryForStationId(ids, headers); Assert.assertNull(result); }