code: def test_undefined_asset_uid():
      a = UndefinedAsset()
      b = UndefinedAsset()
      assert a.uid == "UndefinedAsset"
      assert b.uid == "UndefinedAsset"
  
imports: import re
  import pytest
  import numpy
  from numpy.testing import assert_allclose
  import pyquaternion
  from traitlets import TraitError
  from unittest import mock
  from kubric.core import Asset
  from kubric.core import UndefinedAsset
  from kubric.core import objects
  from kubric.core import materials
label_desc: Use image node_id 5 for calling a global function with example usage: test_undefined_asset_uid() without return types