private Optional<MemberShape> getIdempotencyToken(Model model, OperationShape operation) {
        var input = model.expectShape(operation.getInputShape());
        for (var member : input.members()) {
            if (member.hasTrait(IdempotencyTokenTrait.ID)) {
                return Optional.of(member);
            }
        }
        return Optional.empty();
    }
Provides information about idempotency depending on a number of traits.
smithy-docgen/src/main/java/software/amazon/smithy/docgen/interceptors/IdempotencyInterceptor.java