for example i want create one client, and request two or more contract history data, this is wrong way?
```
app = Client()
app.connect('127.0.0.1', 7497, 0)
threading.Thread(target=app.run).start()
time.sleep(1)
for row in ['AAPL','GOOG']:
app.reqHistoricalData(....)
app.disconnect()
```
the app can not disconnect
?
so i write like this:
```
for row in ['AAPL','GOOG']:
app = Client()
app.connect('127.0.0.1', 7497, 0)
threading.Thread(target=app.run).start()
app.reqHistoricalData(args)
```
then i disconnect on historicalDataEnd function, then it is work fine.
?
so my question is, one client only can do one thing?
?
