def __init__(self, api_key, url=GCM_URL, proxy=None):
        self.api_key = api_key
        self.url = url
        if proxy:
            if isinstance(proxy, basestring):
                protocol = url.split(':')[0]
                proxy = {protocol: proxy}

            auth = urllib2.HTTPBasicAuthHandler()
            opener = urllib2.build_opener(urllib2.ProxyHandler(proxy), auth, urllib2.HTTPHandler)
            urllib2.install_opener(opener)
api_key : google api key
dataset/ETHPy150Open Nordeus/pushkin/pushkin/sender/nordifier/gcm.py/GCM.__init__