code: public List<Notification> getByTarget(Object target) {
          List<Notification> found = new ArrayList<Notification>();
          for (Notification n: NotificationManager.notifications) {
              for (Object t : ((InteractionNotification)n).getTarget()) {
                  if (t.equals(target)){ 
                      logger.fine("...found a match for getByTarget query. With target: "+target);
                      found.add(n);
                  }
              }
          }
          if(found.size()>0)        
              return found;
          return null;
      }
docs: Search for notifications of interaction type that match the given target object
  .
  @param target
  the target object from which notifications are asked.
  @return
  a List with notifications founded that match the given target object.