code: def test_basic(self):
      x = np.arange(-2, 3)
      assert_equal(np.flatnonzero(x), [0, 1, 3, 4])
  
imports: from unittest import skipIf, SkipTest
  import numpy
  import pytest
  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 1 for calling the TestFlatnonzero obj's underlying member method code with example usage: obj.test_basic() without return types