akka event adapter for a top level class in event hierarchy

EventStoreDB
1

I am using akka 2.4 with eventstore 4.0.0.7 and I am new to event adapters

I have a Old event known us UserEvent (Class) which has only one class member known as email. Now I am switching to username and therefore this event variable email changes to username.

I have written a adapter to catch all UserEvent instances using instanceof and then convert it into UserEventV2 and return the new Object

Currently My adapter nor the akka system throws any error on console - But I get username as null, when the domain object is recovered.

Here’s my code

class UserEventEmailToUsername implements EventAdapter {

      @Override
      public String manifest(Object event) {
        return ""; // if no manifest needed, return ""
      }

      @Override
      public Object toJournal(Object event) {
        return event; // identity
      }

      @Override
      public EventSeq fromJournal(Object event, String manifest) {
        if (event instanceof UserEvent) {
          UserEvent evt = (UserEvent) event;
          return EventSeq.single(new UserEventWithUsernameVersion(evt.getEmail()));
        }
        return EventSeq.single(event); // identity
      }
    }

here’s my old event and new event class

@AllArgsConstructor
@ToString
public class UserEvent extends EventWithTimeStamps implements Serializable {
  private static final long serialVersionUID = 1L;
  @Getter private String email;
}

@AllArgsConstructor
@ToString
public class UserEventWithUsernameVersion extends EventWithTimeStamps implements Serializable {
  private static final long serialVersionUID = 1L;
  @Getter private String username;
}

akka configuration

akka.persistence.journal {
      inmem {
        event-adapters {
          userEvent-upcasting = "com.wt.domain.write.events.adapter.UserEventEmailToUsername"
        }

        event-adapter-bindings {
          "com.wt.domain.write.events.UserEvent"    = [userEvent-upcasting]
        }
      }
    }

am I doing something wrong ? if not then why am I getting null value in username ?