private ValidationEvent invalidOperation(Shape shape, HttpTrait trait) {
        return danger(shape, trait, "Expected an `http` code in the 2xx range, but found " + trait.getCode());
    }
Ensures that HTTP response codes are appropriate for operations and errors.
smithy-model/src/main/java/software/amazon/smithy/model/validation/validators/HttpResponseCodeSemanticsValidator.java