code: def _get_tag_fixture():
      """Generate a simple list of test cases for optional return_tags."""
      # just picked a few valid tags to try out as valid str return_tags args:
      test_str_as_arg = [
          "X-y-must-have-same-index",
          "capability:pred_var",
          "skip-inverse-transform",
      ]
  
      # we can also make them into a list to test list of str as a valid arg:
      test_list_as_arg = [test_str_as_arg]
      # Note - I don't include None explicitly as a test case - tested elsewhere
      return test_str_as_arg + test_list_as_arg
  
file_path: sktime/sktime/registry/tests/test_lookup.py
imports: import pytest
  from sktime.base import BaseObject
  from sktime.registry import all_estimators, all_tags, scitype
  from sktime.registry._base_classes import BASE_CLASS_LOOKUP, BASE_CLASS_SCITYPE_LIST, TRANSFORMER_MIXIN_SCITYPE_LIST
  from sktime.registry._lookup import _check_estimator_types
label_desc: Use image node_id 7 for calling a global function with example usage: _get_tag_fixture() and returns: unknown