code: def test_add_func():
      prop_train = Properties(
          "MyStepTrain", shape_name="DescribeTrainingJobResponse"
      )
      prop_model = Properties(
          "MyStepModel", shape_name="DescribeModelPackageOutput"
      )
  
      with pytest.raises(TypeError) as error:
          prop_train + prop_model
  
      assert (
          str(error.value)
          == "Pipeline variables do not support concatenation."
      )
  
file_path: sagemaker-python-sdk/tests/unit/sagemaker/workflow/test_properties.py
imports: from __future__ import absolute_import
  import pytest
  from mock import Mock
  from copy import deepcopy
  from sagemaker.workflow.properties import Properties
  from sagemaker.workflow.step_outputs import get_step
label_desc: Use image node_id 9 for calling a global function with example usage: test_add_func() without return types