code: def test_transfer_files_async(
      self,
      mock_s3_hook,
      mock_gcs_hook,
  ):
      mock_s3_hook.conn_config = mock.MagicMock(
          aws_access_key_id=AWS_ACCESS_KEY_ID,
          aws_secret_access_key=AWS_SECRET_ACCESS_KEY,
      )
      mock_gcs_hook.project_id = PROJECT_ID
      expected_job_names = [TRANSFER_JOB_ID_0]
      expected_method_name = "execute_complete"
  
      operator = S3ToGCSOperator(
          task_id=TASK_ID,
          bucket=S3_BUCKET,
          prefix=S3_PREFIX,
          delimiter=S3_DELIMITER,
          gcp_conn_id=GCS_CONN_ID,
          dest_gcs=GCS_PATH_PREFIX,
      )
  
      with mock.patch.object(
          operator, "submit_transfer_jobs"
      ) as mock_submit_transfer_jobs:
          mock_submit_transfer_jobs.return_value = expected_job_names
          with pytest.raises(TaskDeferred) as exception_info:
              operator.transfer_files_async(
                  files=MOCK_FILES,
                  gcs_hook=mock_gcs_hook,
                  s3_hook=mock_s3_hook,
              )
  
      mock_submit_transfer_jobs.assert_called_once_with(
          files=MOCK_FILES, gcs_hook=mock_gcs_hook, s3_hook=mock_s3_hook
      )
  
      assert hasattr(exception_info.value, "trigger")
      trigger = exception_info.value.trigger
      assert trigger.project_id == PROJECT_ID
      assert trigger.job_names == expected_job_names
      assert trigger.poll_interval == operator.poll_interval
  
      assert hasattr(exception_info.value, "method_name")
      assert exception_info.value.method_name == expected_method_name
  
imports: from __future__ import annotations
  from unittest import mock
  from unittest.mock import PropertyMock
  import pytest
  import time_machine
  from airflow.exceptions import AirflowException, TaskDeferred
  from airflow.providers.google.cloud.hooks.cloud_storage_transfer_service import CloudDataTransferServiceHook
  from airflow.providers.google.cloud.transfers.s3_to_gcs import S3ToGCSOperator
  from airflow.utils.timezone import utcnow
label_desc: Use image node_id 2 for calling the TestS3ToGoogleCloudStorageOperatorDeferrable obj's underlying member method code with example usage: obj.test_transfer_files_async(mock_s3_hook, mock_gcs_hook) without return types