code: def test_2d(self):
      b = np.random.rand(5, 5)
      c = np.random.rand(5, 5)
      d = r_["1", b, c]  # append columns
      assert_(d.shape == (5, 10))
      assert_array_equal(d[:, :5], b)
      assert_array_equal(d[:, 5:], c)
      d = r_[b, c]
      assert_(d.shape == (10, 5))
      assert_array_equal(d[:5, :], b)
      assert_array_equal(d[5:, :], c)
  
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 TestConcatenator obj's underlying member method code with example usage: obj.test_2d() without return types