How to connect to twitter via a proxy server?

[green-bits]

Hi,
my webserver can only communicate to twitter via a proxy server.
I found the following script for proxy server authencation:
api = TwitterAPI(consumer_key,
consumer_secret,
access_token_key,
access_token_secret,
proxy_url='https://USER:PASSWORD@SERVER:PORT')

How can I add the proxy_url to cw_twitter?

Best regards
Ralf