test

self.client = [[MQTTClient alloc]initWithClientId: @"iosapp" cleanSession:YES];
    self.client.username = @"sohta2@github";
    self.client.password = <パスワード>;
    
    NSLog(@"publishToBroker!!!");
    NSLog(@"%@", gMQTTHost);
    [self.client connectToHost:gMQTTHost completionHandler:^(NSUInteger code) {
        NSLog(@"%lu", (unsigned long)code);
        if(code == ConnectionAccepted) {
            NSLog(@"connect accepted!");
        } else {
            NSLog(@"mqtt broker return code:%lu", (unsigned long)code);
            
            switch (code) {
                case ConnectionRefusedUnacceptableProtocolVersion:
                    NSLog(@"connect error! code:%@", @"ConnectionRefusedUnacceptableProtocolVersion");
                    break;
                case ConnectionRefusedServerUnavailable:
                    NSLog(@"connect error! code:%@", @"ConnectionRefusedServerUnavailable");
                    break;
                case ConnectionRefusedBadUserNameOrPassword:
                    NSLog(@"connect error! code:%@", @"ConnectionRefusedBadUserNameOrPassword");
                    break;
                case ConnectionRefusedNotAuthorized:
                    NSLog(@"connect error! code:%@", @"ConnectionRefusedNotAuthorized");
                    break;
                default:
                    break;
            }
            
            NSLog(@"clientId: %@", self.clientId);
            NSLog(@"username: %@", self.client.username);
            NSLog(@"password: %@", self.client.password);
            [self.client disconnectWithCompletionHandler:^(NSUInteger code) {
                // The client is disconnected when this completion handler is called
                NSLog(@"MQTT client is disconnected");
            }];
            self.client = nil;
            return;
        }
    }];
}

if (self.client) {
    [self.client publishString:msg
                       toTopic: @"sohta2@github/example"
                       withQos:AtMostOnce
                        retain:YES
             completionHandler:^(int mid) {
                 NSLog(@"mid:%d", mid);
                 NSLog(@"message has been delivered");
             }
     ];
}