docstr: Tests main exits with error on failed docker login
docstr_tok: ["Tests","main","exits","with","error","on","failed","docker","login"]
code: def test_main_exit(self, mock_login):
      """
      Tests main exits with error on failed docker login
      """
      mock_login.side_effect = RuntimeError("Didn't work")
      with self.assertRaises(SystemExit):
          main(
              [
                  "--secret-name",
                  "name",
                  "--secret-endpoint-url",
                  "url",
                  "--secret-endpoint-region",
                  "r",
              ]
          )
  
file_path: mxnet/ci/test_docker_login.py
imports: import os
  import subprocess
  import unittest
  from unittest.mock import create_autospec, patch, call, MagicMock
  import boto3
  from boto3 import client
  from botocore.stub import Stubber
  from docker_login import login_dockerhub, logout_dockerhub, main, DOCKERHUB_RETRY_SECONDS, DOCKERHUB_LOGIN_NUM_RETRIES
label_desc: Use image node_id 6 for calling the TestDockerLogin obj's underlying member method code with example usage: obj.test_main_exit(mock_login) without return types