code: def test_operate_4d_array(self):
      a = np.zeros((3, 3, 3, 3), dtype=int)
      fill_diagonal(a, 4)
      i = np.array([0, 1, 2])
      assert_equal(np.where(a != 0), (i, i, i, i))
  
imports: import functools
  from unittest import expectedFailure, skipIf
  from pytest import raises
  from torch.testing._internal.common_utils import instantiate_parametrized_tests, parametrize, run_tests, TEST_WITH_TORCHDYNAMO, TestCase, xpassIfTorchDynamo
label_desc: Use image node_id 5 for calling the TestFillDiagonal obj's underlying member method code with example usage: obj.test_operate_4d_array() without return types