code: def get_all_subscriptions(self, next_token=None):
          
          params = {'ContentType' : 'JSON'}
          if next_token:
              params['NextToken'] = next_token
          response = self.make_request('ListSubscriptions', params, '/', 'GET')
          body = response.read()
          if response.status == 200:
              return json.loads(body)
          else:
              boto.log.error('%s %s' % (response.status, response.reason))
              boto.log.error('%s' % body)
              raise self.ResponseError(response.status, response.reason, body)
docs: Get list of all subscriptions.
  
          :type next_token: string
          :param next_token: Token returned by the previous call to
                             this method.