code: def process(self, event):
          
  
          conf = settings.WALDUR_CORE.get('GOOGLE_API') or {}
          keys = conf.get(dict(self.Type.CHOICES)[self.type])
  
          if not keys or not self.token:
              return
  
          endpoint = 'https://gcm-http.googleapis.com/gcm/send'
          headers = {
              'Content-Type': 'application/json',
              'Authorization': 'key=%s' % keys['server_key'],
          }
          payload = {
              'to': self.token,
              'notification': {
                  'body': event.get('message', 'New event'),
                  'title': conf.get('NOTIFICATION_TITLE', 'Waldur notification'),
                  'image': 'icon',
              },
              'data': {
                  'event': event
              },
          }
          if self.type == self.Type.IOS:
              payload['content-available'] = '1'
          logger.debug('Submitting GCM push notification with headers %s, payload: %s' % (headers, payload))
          requests.post(endpoint, json=payload, headers=headers)
docs: Send events as push notification via Google Cloud Messaging.
              Expected settings as follows:
  
                  # https://developers.google.com/mobile/add
                  WALDUR_CORE['GOOGLE_API'] = {
                      'NOTIFICATION_TITLE': "Waldur notification",
                      'Android': {
                          'server_key': 'AIzaSyA2_7UaVIxXfKeFvxTjQNZbrzkXG9OTCkg',
                      },
                      'iOS': {
                          'server_key': 'AIzaSyA34zlG_y5uHOe2FmcJKwfk2vG-3RW05vk',
                      }
                  }