code: def test_error_if_init_without_token(self):
      # copy environment variables but remove LIGHTLY_TOKEN if it exists
      env_without_token = {
          k: v for k, v in os.environ.items() if k != "LIGHTLY_TOKEN"
      }
      with self.assertRaises(ValueError), mock.patch.dict(
          os.environ, env_without_token, clear=True
      ):
          MockedApiWorkflowClient()
  
file_path: lightly/tests/api_workflow/test_api_workflow.py
imports: import os
  from unittest import mock
  import numpy
  import lightly
  from tests.api_workflow import utils
  from tests.api_workflow.mocked_api_workflow_client import MockedApiWorkflowClient, MockedApiWorkflowSetup
label_desc: Use image node_id 3 for calling the TestApiWorkflow obj's underlying member method code with example usage: obj.test_error_if_init_without_token() without return types