@Override
 public void handleTimeout(InetAddress address, EchoPacket request) {
   String oldPrefix = ThreadCategory.getPrefix();
   try {
     ThreadCategory.setPrefix(m_prefix);
     m_cb.handleTimeout(address, request);
   } finally {
     ThreadCategory.setPrefix(oldPrefix);
   }
 }
 @Override
 public void handleResponse(InetAddress address, EchoPacket response) {
   String oldPrefix = ThreadCategory.getPrefix();
   try {
     ThreadCategory.setPrefix(m_prefix);
     m_cb.handleResponse(address, response);
   } finally {
     ThreadCategory.setPrefix(oldPrefix);
   }
 }