code: def cancel_spot_instance_requests(self, request_ids):
          
          params = {}
          if request_ids:
              self.build_list_params(params, request_ids, 'SpotInstanceRequestId')
          return self.get_list('CancelSpotInstanceRequests', params,
                               [('item', Instance)], verb='POST')
docs: Cancel the specified Spot Instance Requests.
  
          :type request_ids: list
          :param request_ids: A list of strings of the Request IDs to terminate
  
          :rtype: list
          :return: A list of the instances terminated