'Constructor
@param channel: dict with Google API credentials:
{id=clientID, secret=clientSecret}'

def __init__(self, channel):

    settings = current.deployment_settings
    scope = 'https://www.googleapis.com/auth/userinfo.email    https://www.googleapis.com/auth/userinfo.profile'
    user_agent = 'google-api-client-python-plus-cmdline/1.0'
    redirect_uri = ('%s/%s/default/google/login' % (settings.get_base_public_url(), current.request.application))
    OAuthAccount.__init__(self, client_id=channel['id'], client_secret=channel['secret'], auth_url=self.AUTH_URL, token_url=self.TOKEN_URL, scope=scope, user_agent=user_agent, xoauth_displayname=settings.get_system_name(), response_type='code', redirect_uri=redirect_uri, approval_prompt='force', state='google')
    self.graph = None
