def METHOD_NAME(request):
    channel = request.GET['channel']
    if channel is None:
        return _internal_server_error({
            "error": "Channel missing"
        })
    try:
        pubnub.unsubscribe().channels(channel).execute()
        return _ok({
            "subscribed_channels": pubnub.get_subscribed_channels()
        })
    except PubNubException as e:
        return _internal_server_error({
            "message": str(e)
        })