code: func (rpcClient *ReconnectRPCClient) Close() (err error) {
  	rpcClient.mutex.Lock()
  	netRPCClient := rpcClient.netRPCClient
  	rpcClient.mutex.Unlock()
  
  	if netRPCClient != nil {
  		var status bool
  		netRPCClient.Call("LockServer.Logout", &rpcClient.sessionID, &status)
  
  		rpcClient.mutex.Lock()
  		rpcClient.netRPCClient = nil
  		rpcClient.mutex.Unlock()
  
  		netRPCClient.Close()
  	}
  
  	return nil
  }
docs: // Close closes the underlying socket file descriptor.