purgeClasses();
  private void purge() {    Enumeration keys = m_TaskStatus.keys();    long currentTime = System.currentTimeMillis();    System.err.println("RemoteEngine purge. Current time : " + currentTime);    while (keys.hasMoreElements()) {      String tk = (String)keys.nextElement();      System.err.print("Examining task id : " + tk + "...");      String timeString = tk.substring(0, tk.indexOf(':'));      long ts = Long.valueOf(timeString).longValue();      if (currentTime - ts > 3600000) {	TaskStatusInfo tsi = null;	tsi = (TaskStatusInfo)m_TaskStatus.get(tsi);	if ((tsi != null) 	    && (tsi.getExecutionStatus() == TaskStatusInfo.FINISHED ||	    tsi.getExecutionStatus() == TaskStatusInfo.FAILED)) {	  System.err.println("\nTask id : " 			     + tk + " has gone stale. Removing.");	  m_TaskStatus.remove(tk);	}      } else {	System.err.println("ok.");      }    }  }