@Test
    public void withPreflightIntegrationSync() {
        Model model = Model.assembler(getClass().getClassLoader())
                .discoverModels(getClass().getClassLoader())
                .addImport(getClass().getResource("cors-with-multi-request-templates.json"))
                .assemble()
                .unwrap();
        OpenApiConfig config = new OpenApiConfig();
        config.setService(ShapeId.from("example.smithy#MyService"));
        config.setSyncCorsPreflightIntegration(true);
        ObjectNode result = OpenApiConverter.create().config(config).convertToNode(model);
        Node expectedNode = Node.parse(IoUtils.toUtf8String(
                getClass().getResourceAsStream("cors-with-preflight-sync.openapi.json")));

        Node.assertEquals(result, expectedNode);
    }
This test asserts two things: First, it ensures that any existing CORS headers
set on an explicitly added API Gateway integration are not overwritten
(i.e., the "Access-Control-Allow-Origin" is "domain.com" instead of https://foo.com).
Next, it asserts that any other headers in the gateway response show up in the
injected Access-Control-Expose-Headers header.
smithy-aws-apigateway-openapi/src/test/java/software/amazon/smithy/aws/apigateway/openapi/CorsTest.java