Not working with Electron about mqtt HOT 2 CLOSED

        while (!_client->available()) {
            unsigned long t = millis();
            if (t-lastInActivity > MQTT_KEEPALIVE*1000UL) {
                _client->stop();
                Serial.println("can't read from server packet");
                return false;
            }
        }

        uint8_t llen;
        uint16_t len = readPacket(&llen);
        Serial.print("read packet length : ");
        Serial.println("len");

        if (len == 4 && buffer[3] == 0) {
            lastInActivity = millis();
            pingOutstanding = false;
            Serial.println("read packet OK");
            return true;
        }
    }
    Serial.println("read packet fail");
    _client->stop();