code: def test_ellipsis_invalid_identifier(self) -> None:
      axes_lengths: Dict[str, int] = {"a": 1, _ellipsis: 2}
      pattern = f"a {_ellipsis} -> {_ellipsis} a"
      with self.assertRaises(ValueError):
          parse_pattern(pattern, axes_lengths)
  
imports: from typing import Any, Callable, Dict
  from unittest import mock
  from functorch.einops._parsing import AnonymousAxis, ParsedExpression, parse_pattern, validate_rearrange_expressions, _ellipsis
  from torch.testing._internal.common_utils import TestCase, run_tests
label_desc: Use image node_id 2 for calling the TestParsingUtils obj's underlying member method code with example usage: obj.test_ellipsis_invalid_identifier() without return types