code: def test_dataset_id_nonexisting(self):
      self.api_workflow_client._datasets_api.reset()
      assert not hasattr(self.api_workflow_client, "_dataset_id")
      with self.assertWarns(UserWarning):
          dataset_id = self.api_workflow_client.dataset_id
      assert (
          dataset_id
          == self.api_workflow_client._datasets_api.datasets[-1].id
      )
  
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 5 for calling the TestApiWorkflow obj's underlying member method code with example usage: obj.test_dataset_id_nonexisting() without return types