code: def test_dtypes(self):
      c = array([11, -12, 13], dtype=np.int8)
      v = vander(c)
      expected = np.array([[121, 11, 1], [144, -12, 1], [169, 13, 1]])
      assert_array_equal(v, expected)
  
      c = array([1.0 + 1j, 1.0 - 1j])
      v = vander(c, N=3)
      expected = np.array([[2j, 1 + 1j, 1], [-2j, 1 - 1j, 1]])
      # The data is floating point, but the values are small integers,
      # so assert_array_equal *should* be safe here (rather than, say,
      # assert_array_almost_equal).
      assert_array_equal(v, expected)
  
imports: import functools
  from unittest import expectedFailure, skipIf
  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 2 for calling the TestVander obj's underlying member method code with example usage: obj.test_dtypes() without return types