code: def test_var_names_filter_invalid_argument():
      """Check invalid argument raises."""
      samples = np.random.randn(10)
      data = dict_to_dataset({"alpha": samples})
      msg = r"^\'filter_vars\' can only be None, \'like\', or \'regex\', got: 'foo'$"
      with pytest.raises(ValueError, match=msg):
          assert _var_names(["alpha"], data, filter_vars="foo")
  
imports: from unittest.mock import Mock
  import numpy
  import pytest
  import scipy.stats
  from ...data import dict_to_dataset, from_dict, load_arviz_data
  from ...stats.density_utils import _circular_mean, _normalize_angle, _find_hdi_contours
  from ...utils import _stack, _subset_list, _var_names, expand_dims, flatten_inference_data_to_dict, one_de, two_de
  from ..helpers import TestRandomVariable
label_desc: Use image node_id 9 for calling a global function with example usage: test_var_names_filter_invalid_argument() without return types