@Override
    public void updateDefaultSettings(Model model, OpenApiConfig openApiConfig) {
        ApiGatewayConfig config = openApiConfig.getExtensions(ApiGatewayConfig.class);
        if (config.getApiGatewayDefaults() == null) {
            LOGGER.warning(String.format("`apiGatewayDefaults` configuration not set for openapi plugin. Assuming %s.",
                    DEFAULT_VERSION));
            config.setApiGatewayDefaults(DEFAULT_VERSION);
        }
        config.getApiGatewayDefaults().setDefaults(openApiConfig);
    }
Sets default config settings for API Gateway.

<p>By default, this disables OpenAPI and JSON Schema features not
supported by API Gateway.</p>

<p>API Gateway does not allow characters like "_". API Gateway
doesn't support the "default" trait or `int32` or `int64` "format"
values.
smithy-aws-apigateway-openapi/src/main/java/software/amazon/smithy/aws/apigateway/openapi/AddDefaultConfigSettings.java