Esper EPL aggregation with custom function

I am trying to do an aggregation with Esper 8.8.0 EPL using the following code. When ProductEvent is published then I am trying to save it into a table after converting the complete ProductEvent bean object into json. Is there any way I can pass ProductEven Object itself in custom function when executing merge statement -

@public create table OutputTable
(
productId string primary key
, productName string
, productJson   string
);



@name('stmtUpdateOutputTable') on ProductEvent pe
merge OutputTable ot
where ot.productId = pe.productId
when not matched
  then insert select productId, productName, Utils.getJson(*)
when matched
  then update
    set            
        ot.productName= pe.productName,
        ot.productJson  = Utils.getJson(*)
        ;

ProductEvent is a java bean that contains more than 100 property so it is not a good idea I pass each individual field when call custom function -

public class ProductEvent{
    private String productId;
    private String productName;
    private Double price;
    private LocalDate firstAvailableDate;
    //..... around 100 more properties here
}

Utils is a helper class that contains static method -

public static String getJson(ProductEvent  event) {       
    return new ObjectMapper().writeValueAsString(event);
}

In the on-merge, there are two aliases: "pe" for ProductEvent and "ot" for OutputTable, so "...Utils.getJson(pe)..." would work.