We have a DynamoDB table Test which has an attribute Template. Bellow are the class definitions. I would like to update the Template attribute or some of its attribute based on certain condition. I tried doing the same using UpdateItemRequest but unable to find a way to update the template attribute since everything is converted to either string, number or bytes.

Code for reference.

```
@DynamoDbBean
public class Test implements NoSQLEntity {

private String name;
private Template template;

@DynamoDbAttribute("name")
public String getName() {
    return name;
}

@DynamoDbAttribute("template")
public Template getTemplate() {
     return template;
}   
}

   @DynamoDbBean
   public class Template {

   private String pk;
   private String name;
   private List<String> demo;

   @DynamoDbAttribute("pk")
   public String getPk() {
        return this.pk;
   }

   @DynamoDbAttribute("name")
   public String getName() {
         return name;
   }

   @DynamoDbAttribute("demo")
   public List<String> getdemo() {
       return demo;
   } 

}

```

Sample update code:

```
UpdateItemRequest request = UpdateItemRequest.builder()
            .tableName("Test")
            .key(itemKey)
            .updateExpression("SET tmpt = :tmt")
            .expressionAttributeValues(expressionValues)
            .build();

```

Here I am unable to build the :tmt using the AttributeValue. Can someone please guide me?