code: def test_unset_repr(capsys):
      def fn(a=UNSET):
          return
  
      help(fn)
      captured = capsys.readouterr()
      assert "a=UNSET" in captured.out
  
imports: import re
  import arviz
  import numpy
  import pytest
  import xarray
  from cachetools import cached
  import pymc
  from pymc.distributions.transforms import Transform
  from pymc.util import UNSET, _get_seeds_per_chain, dataset_to_point_list, drop_warning_stat, get_value_vars_from_user_vars, hash_key, hashable, locally_cachedmethod
label_desc: Use image node_id 3 for calling a global function with example usage: test_unset_repr(capsys) without return types