code: def test_has_creds_file_with_valid_s3_link(self, mock_get):
      # Configure the mock behavior
      mock_response = mock_get.return_value
      mock_response.status_code = 200
      mock_response.text = "Mocked credentials file content"
  
      result = self.handler._has_creds_file(self.credentials_file)
      # Assert that the requests.get method was called with the correct URL
      mock_get.assert_called_once_with(self.credentials_url)
      # Assert that the method returns True
      self.assertTrue(result)
  
imports: from mindsdb.api.executor.data_types.response_type import RESPONSE_TYPE
  from mindsdb.integrations.handlers.gmail_handler.gmail_handler import GmailHandler
  from mindsdb.integrations.handlers.gmail_handler.gmail_handler import EmailsTable
  from google.oauth2.credentials import Credentials
  from mindsdb_sql import parse_sql
  import unittest
  from unittest.mock import Mock, patch
  from unittest import mock
label_desc: Use image node_id 2 for calling the GmailHandlerTest obj's underlying member method code with example usage: obj.test_has_creds_file_with_valid_s3_link(mock_get) without return types