state.getToAck().clear();
state.getClientAckList().clear();
   public Object handleAcknowledgeAll(Invocation invocation) throws Throwable   {          MethodInvocation mi = (MethodInvocation)invocation;      SessionState state = getState(invocation);      SessionDelegate del = (SessionDelegate)mi.getTargetObject();          if (!state.getToAck().isEmpty())      {                           del.acknowledgeBatch(state.getToAck());               state.getToAck().clear();      }              return null;   }