### Question:
StoreApi { public Order getOrderById(Long orderId) throws ApiException { Object localVarPostBody = null; if (orderId == null) { throw new ApiException(400, "Missing the required parameter 'orderId' when calling getOrderById"); } String localVarPath = "/store/order/{order_id}" .replaceAll("\\{" + "order_id" + "\\}", apiClient.escapeString(orderId.toString())); List<Pair> localVarQueryParams = new ArrayList<Pair>(); List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>(); Map<String, String> localVarHeaderParams = new HashMap<String, String>(); Map<String, String> localVarCookieParams = new HashMap<String, String>(); Map<String, Object> localVarFormParams = new HashMap<String, Object>(); final String[] localVarAccepts = { "application/xml", "application/json" }; final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts); final String[] localVarContentTypes = { }; final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes); String[] localVarAuthNames = new String[] { }; GenericType<Order> localVarReturnType = new GenericType<Order>() {}; return apiClient.invokeAPI(localVarPath, "GET", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, localVarReturnType); } StoreApi();  StoreApi(ApiClient apiClient); ApiClient getApiClient(); void setApiClient(ApiClient apiClient); void deleteOrder(String orderId); Map<String, Integer> getInventory(); Order getOrderById(Long orderId); Order placeOrder(Order body);  }### Answer:
@Test public void getOrderByIdTest() throws ApiException { Long orderId = null; Order response = api.getOrderById(orderId); }