Dyanmodb Enchanced client nested Objects as json

I have nested Object (composition) use to represent data that i want to store and using Dyanmodb enhanced client as part of AWS Java version 2 api. In the readme it explains how to flatten the objects. In the version one of the api was able to store list of objects as json documents in dyanmodb. Would like it to be stored as Json not flattened for backward compatibility:

## Steps to Reproduce
```
public class Customer{
private String name;
private List recordMetadata;
//getters and setters for all attributes
}

public class GenericRecord {
private String id;
private String details;
//getters and setters for all attributes
}
```
Would like it to be stored as below not flattened for backward compatibility:
```
{
"name": "ABC",
"recordMetadata": [
{
"id":"123",
"details":"hello"

},
{
"id":"456",
"details":"yellow"

}
]

}
```
## Current Behavior
In the readme it only describe how to flatten

https://github.com/aws/aws-sdk-java-v2/blob/master/services-custom/dynamodb-enhanced/README.md

## Your Environment

* AWS Java SDK version used: 2.15.72