class_docstr: Google Storage Transfer Service functionalities.
  
  All methods in the hook with *project_id* in the signature must be called
  with keyword arguments rather than positional.
docstr: Retrieve connection to Google Storage Transfer service.
  
  :return: Google Storage Transfer service object
code: def get_conn(self) -> Resource:
      """Retrieve connection to Google Storage Transfer service.
  
      :return: Google Storage Transfer service object
      """
      if not self._conn:
          http_authorized = self._authorize()
          self._conn = build(
              "storagetransfer",
              self.api_version,
              http=http_authorized,
              cache_discovery=False,
          )
      return self._conn
  
imports: from __future__ import annotations
  import json
  import logging
  import time
  import warnings
  from copy import deepcopy
  from datetime import timedelta
  from typing import TYPE_CHECKING, Any, Sequence
  from google.cloud.storage_transfer_v1 import ListTransferJobsRequest, StorageTransferServiceAsyncClient, TransferJob, TransferOperation
  from googleapiclient.discovery import Resource, build
  from googleapiclient.errors import HttpError
  from airflow.exceptions import AirflowException, AirflowProviderDeprecationWarning
  from airflow.providers.google.common.hooks.base_google import GoogleBaseAsyncHook, GoogleBaseHook
label_desc: Use image node_id 2 for calling the CloudDataTransferServiceHook obj's underlying member method code with example usage: obj.get_conn() and returns: self