client = mqtt.Client(client_id="myclientid",clean_session=False)

client.on_connect = on_connect
client.on_message = on_message

client.connect("localhost",1883,60)
client.loop_forever()
```

Execute this example python program to watch for MQTT events on the console.

```py
python mqtt.py
```

        // Setting onConnect to null should work
        request.onConnect(null);

        assertNotNull(request);
    }

    @Test
    public void testMultipleOnConnectCalls() {
        CurlRequest request = new CurlRequest(Method.GET, "https://example.com");

        // Multiple onConnect calls should work (last one wins)
        request.onConnect((req, conn) -> conn.setConnectTimeout(1000));

// Op is operation type messages.
type Op uint8

// HandlerID is the ID for the handler of a specific type.
type HandlerID uint8

const (
	// OpConnect is a connect request.
	OpConnect Op = iota + 1

	// OpConnectResponse is a response to a connect request.
	OpConnectResponse

	// OpPing is a ping request.
	// If a mux id is specified that mux is pinged.

package grid

import "strconv"

func _() {
	// An "invalid array index" compiler error signifies that the constant values have changed.
	// Re-run the stringer command to generate them again.
	var x [1]struct{}
	_ = x[OpConnect-1]
	_ = x[OpConnectResponse-2]
	_ = x[OpPing-3]
	_ = x[OpPong-4]
	_ = x[OpConnectMux-5]
	_ = x[OpMuxConnectError-6]
	_ = x[OpDisconnectClientMux-7]
	_ = x[OpDisconnectServerMux-8]
	_ = x[OpMuxClientMsg-9]

      }

      OverrideParam.ConnectTimeout -> {
        client =
          client
            .newBuilder()
            .socketFactory(
              DelayingSocketFactory(onConnect = { timeout ->
                if (timeout == 10) {
                  throw IOException()
                }
              }),
            ).build()

        }

        final ObjectMapper mapper = new ObjectMapper();
        final AtomicBoolean resetJobs = new AtomicBoolean(false);
        try (CurlResponse response = ComponentUtil.getCurlHelper().post("/_bulk").onConnect((req, con) -> {
            con.setDoOutput(true);
            try (final BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(tempFile)));

			}
			c.updateState(StateConnectionError)
			time.Sleep(sleep)
		}
		if err != nil {
			retry(err)
			continue
		}
		// Send connect message.
		m := message{
			Op: OpConnect,
		}
		req := connectReq{
			Host: c.Local,
			ID:   c.id,
			Time: time.Now(),
		}
		req.addToken(c.authFn)
		err = c.sendMsg(conn, m, &req)
		if err != nil {
			retry(err)
			continue