### Question:
StoreApi { public CompletableFuture<Order> getOrderById(Long orderId) throws ApiException { try { HttpRequest.Builder localVarRequestBuilder = getOrderByIdRequestBuilder(orderId); return memberVarHttpClient.sendAsync( localVarRequestBuilder.build(), HttpResponse.BodyHandlers.ofString()).thenComposeAsync(localVarResponse -> { if (localVarResponse.statusCode()/ 100 != 2) { return CompletableFuture.failedFuture(getApiException("getOrderById", localVarResponse)); } try { return CompletableFuture.completedFuture( memberVarObjectMapper.readValue(localVarResponse.body(), new TypeReference<Order>() {}) ); } catch (IOException e) { return CompletableFuture.failedFuture(new ApiException(e)); } }); } catch (ApiException e) { return CompletableFuture.failedFuture(e); } } StoreApi();  StoreApi(ApiClient apiClient); CompletableFuture<Void> deleteOrder(String orderId); CompletableFuture<ApiResponse<Void>> deleteOrderWithHttpInfo(String orderId); CompletableFuture<Map<String, Integer>> getInventory(); CompletableFuture<ApiResponse<Map<String, Integer>>> getInventoryWithHttpInfo(); CompletableFuture<Order> getOrderById(Long orderId); CompletableFuture<ApiResponse<Order>> getOrderByIdWithHttpInfo(Long orderId); CompletableFuture<Order> placeOrder(Order body); CompletableFuture<ApiResponse<Order>> placeOrderWithHttpInfo(Order body);  }### Answer:
@Test public void getOrderByIdTest() throws ApiException { Long orderId = null; CompletableFuture<Order> response = api.getOrderById(orderId); }