@Override
    public OperationObject updateOperation(
            Context<? extends Trait> context,
            OperationShape shape,
            OperationObject operation,
            String httpMethod,
            String path
    ) {
        return shape.getTrait(RequestValidatorTrait.class)
                .map(RequestValidatorTrait::getValue)
                .map(value -> operation.toBuilder().putExtension(REQUEST_VALIDATOR, value).build())
                .orElse(operation);
    }
Adds the API Gateway x-amazon-apigateway-request-validators object
to the service and x-amazon-apigateway-request-validator to the
service/operations.

<p>Any operation or service shape with the {@link RequestValidatorTrait}
applied to it will cause that operation to have the {@code x-amazon-apigateway-request-validator}
extension, and adds a {@code x-amazon-apigateway-request-validators} extension
to the top-level OpenAPI document.

@see <a href="https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-swagger-extensions-request-validators.html">Request validators</a>
smithy-aws-apigateway-openapi/src/main/java/software/amazon/smithy/aws/apigateway/openapi/AddRequestValidators.java