code: protected boolean isConnectionOk(IoSession session) {
          SocketAddress remoteAddress = session.getRemoteAddress();
          if (remoteAddress instanceof InetSocketAddress) {
              InetSocketAddress addr = (InetSocketAddress) remoteAddress;
              long now = System.currentTimeMillis();
  
              if (clients.containsKey(addr.getAddress().getHostAddress())) {
  
                  LOGGER.debug("This is not a new client");
                  Long lastConnTime = clients.get(addr.getAddress()
                          .getHostAddress());
  
                  clients.put(addr.getAddress().getHostAddress(), now);
  
                  // if the interval between now and the last connection is
                  // less than the allowed interval, return false
                  if (now - lastConnTime < allowedInterval) {
                      LOGGER.warn("Session connection interval too short");
                      return false;
                  }
                  
                  return true;
              }
  
              clients.put(addr.getAddress().getHostAddress(), now);
              return true;
          }
  
          return false;
      }
docs: Method responsible for deciding if a connection is OK
  to continue
  
  @param session
  The new session that will be verified
  @return
  True if the session meets the criteria, otherwise false