return pongMsg{Err: &err}
	default:
		atomic.StoreInt64(&m.LastPing, time.Now().Unix())
		return pongMsg{}
	}
}

// disconnect will disconnect the mux.
// m.recvMu must be locked when calling this function.
func (m *muxServer) disconnect(msg string, locked bool) {
	if debugPrint {
		fmt.Println("Mux", m.ID, "disconnecting. Reason:", msg)
	}
	if msg != "" {

        }
        ftpAuthenticationHolder = null;
        for (final FTPClient ftpClient : ftpClientQueue) {
            try {
                ftpClient.disconnect();
            } catch (final IOException e) {
                logger.debug("Failed to disconnect FTPClient.", e);
            }
        }
    }

    /*
     * (non-Javadoc)
     *

	OpConnectMux

	// OpMuxConnectError is an  error while connecting a mux.
	OpMuxConnectError

	// OpDisconnectClientMux instructs a client to disconnect a mux
	OpDisconnectClientMux

	// OpDisconnectServerMux instructs a server to disconnect (cancel) a server mux
	OpDisconnectServerMux

	// OpMuxClientMsg contains a message to a client Mux
	OpMuxClientMsg

	}
	if debugPrint {
		fmt.Println("Connecting Mux", m.MuxID, ",to", m.parent.Remote)
	}

	// Space for one message and an error.
	responseCh := make(chan Response, 1)

	// Spawn simple disconnect
	if requests == nil {
		go m.handleOneWayStream(responseCh, responses)
		return &Stream{responses: responseCh, Requests: nil, ctx: m.ctx, cancel: m.cancelFn, muxID: m.MuxID}, nil
	}

	biggerBufMax = maxBufferSize

	// If there is a queue, merge up to this many messages.
	maxMergeMessages = 50

	// clientPingInterval will ping the remote handler every 15 seconds.
	// Clients disconnect when we exceed 2 intervals.
	clientPingInterval = 15 * time.Second

	// Deadline for single (non-streaming) requests to complete.
	// Used if no deadline is provided on context.
	defaultSingleRequestTimeout = time.Minute

// the last peer to connect and the first peer to disconnect.
// This is to improve the RX throughput accuracy.
type netPerfRX struct {
	RX                uint64    // RX bytes
	lastToConnect     time.Time // time at which last peer to connect to us
	firstToDisconnect time.Time // time at which the first peer disconnects from us
	RXSample          uint64    // RX bytes between lastToConnect and firstToDisconnect

	if incoming {
		if debugPrint {
			fmt.Println("deleteMux: disconnect incoming mux", muxID)
		}
		v, loaded := c.inStream.LoadAndDelete(muxID)
		if loaded && v != nil {
			gridLogIf(c.ctx, c.queueMsg(message{Op: OpDisconnectClientMux, MuxID: muxID}, nil))
			v.close()
		}
	} else {
		if debugPrint {
			fmt.Println("deleteMux: disconnect outgoing mux", muxID)
		}

	}

	return target.send(eventData)
}

// Close - does nothing and available for interface compatibility.
func (target *MQTTTarget) Close() error {
	if target.client != nil {
		target.client.Disconnect(100)
	}
	close(target.quitCh)
	return nil
}

func (target *MQTTTarget) init() error {
	return target.initOnce.Do(target.initMQTT)
}

func (target *MQTTTarget) initMQTT() error {

Now, to be able to test that everything works, create a *path operation*:

{* ../../docs_src/custom_docs_ui/tutorial002.py hl[39:41] *}

### Test Static Files UI

Now, you should be able to disconnect your WiFi, go to your docs at <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>, and reload the page.

		w.Header().Set("Content-Type", string(contentType))

		enc := expfmt.NewEncoder(w, contentType)
		for _, mf := range mfs {
			if err := enc.Encode(mf); err != nil {
				// client may disconnect for any reasons
				// we do not have to log this.
				return
			}
		}
		if closer, ok := enc.(expfmt.Closer); ok {
			closer.Close()
		}
	})
}

// NoAuthMiddleware no auth middle ware.