code: def test_get_max_feature_index(self) -> None:
      mask = (
          torch.tensor([[0, 1], [2, 3]]),
          torch.tensor([]),
          torch.tensor([[4, 5], [6, 100]]),
          torch.tensor([[0, 1], [2, 3]]),
      )
  
      assert _get_max_feature_index(mask) == 100
  
imports: from typing import cast, List, Tuple
  import torch
  from captum._utils.common import _format_feature_mask, _get_max_feature_index, _parse_version, _reduce_list, _select_targets, _sort_key_list, safe_div
  from tests.helpers.basic import assertTensorAlmostEqual, assertTensorTuplesAlmostEqual, BaseTest
label_desc: Use image node_id 12 for calling the Test obj's underlying member method code with example usage: obj.test_get_max_feature_index() without return types