Empty list produces a single </listName> instead of nothing

For example i have these classes and interfaces:

public interface Payload {
public String getType();
}

public class Session implements Payload {
private String startTime;
private String entTime;
private List events = new ArrayList();
....
}

public class Message {
private Payload payload;
...
public String toXML()

{ XStream xstream = new XStream(); .... xstream.alias("message", Message.class); xstream.alias("payload", Payload.class); xstream.alias("event", EventLog.class); xstream.alias("session", Session.class); return xstream.toXML(this); }

}

when i use the method, if the ArrayList is empty, it produces a single </events> in the xml string where the events are supposed to be instead of producing nothing for the events. i know xstream has problem with inheritance but i am not sure if this is the case.