code: public Object unmarshal(HierarchicalStreamReader reader,
  			UnmarshallingContext context) {
  		XFactory factory = XFactoryRegistry.instance().currentDefault();
  		XTrace trace = factory.createTrace();
  		reader.moveDown();
  		XAttributeMap attributes = (XAttributeMap) context.convertAnother(
  				trace, XAttributeMap.class,
  				XesXStreamPersistency.attributeMapConverter);
  		trace.setAttributes(attributes);
  		reader.moveUp();
  		while (reader.hasMoreChildren()) {
  			reader.moveDown();
  			XEvent event = (XEvent) context.convertAnother(trace, XEvent.class,
  					XesXStreamPersistency.eventConverter);
  			trace.add(event);
  			reader.moveUp();
  		}
  		return trace;
  	}
docs: /*
  (non-Javadoc)
  
  @see
  com.thoughtworks.xstream.converters.Converter#unmarshal(com.thoughtworks
  .xstream.io.HierarchicalStreamReader,
  com.thoughtworks.xstream.converters.UnmarshallingContext)