code: def mock_session():
      boto_mock = Mock(name="boto_session", region_name=REGION)
      session_mock = Mock(
          name="sagemaker_session",
          boto_session=boto_mock,
          boto_region_name=REGION,
          config=None,
          local_mode=False,
          default_bucket_prefix="abc",
          sagemaker_config=None,
      )
      session_mock.upload_data = Mock(
          name="upload_data", return_value="s3_uri_to_uploaded_data"
      )
      session_mock.download_data = Mock(name="download_data")
      session_mock.get_caller_identity_arn = Mock(
          name="get_caller_identity_arn", return_value=ROLE
      )
      session_mock.default_bucket = Mock(
          name="default_bucket", return_value=DEFAULT_S3_BUCKET
      )
      session_mock.expand_role = Mock(
          name="expand_role", return_value=ROLE
      )
      return session_mock
  
imports: from __future__ import absolute_import
  import unittest
  from mock import Mock, patch
  from sagemaker.workflow.notebook_job_step import NotebookJobStep
  from sagemaker.workflow.functions import Join
label_desc: Use image node_id 1 for calling a global function with example usage: mock_session() and returns: session_mock