docs: public Waiter<DescribeExportTasksRequest> exportTaskCancelled() {
  
          return new WaiterBuilder<DescribeExportTasksRequest, DescribeExportTasksResult>().withSdkFunction(new DescribeExportTasksFunction(client))
                  .withAcceptors(new ExportTaskCancelled.IsCancelledMatcher())
                  .withDefaultPollingStrategy(new PollingStrategy(new MaxAttemptsRetryStrategy(40), new FixedDelayStrategy(15)))
                  .withExecutorService(executorService).build();
      }