private List<ValidationEvent> validateOperations(
            ServiceShape service,
            Set<OperationShape> operations,
            Severity severity,
            String reason
    ) {
        return operations.stream()
                .filter(operation -> !operation.hasTrait(HttpTrait.ID))
                .map(operation -> createEvent(severity,
                        operation,
                        operation.getSourceLocation(),
                        String.format("%s operations in the `%s` service define the `http` trait, but this "
                                + "operation is missing the `http` trait.", reason, service.getId())))
                .collect(Collectors.toList());
    }
Validates that if any operation in a service uses the http trait,
then all operations use them.
smithy-model/src/main/java/software/amazon/smithy/model/validation/validators/HttpBindingsMissingValidator.java