code: def test_0d(self):
      assert_equal(r_[0, np.array(1), 2], [0, 1, 2])
      assert_equal(r_[[0, 1, 2], np.array(3)], [0, 1, 2, 3])
      assert_equal(r_[np.array(0), [1, 2, 3]], [0, 1, 2, 3])
  
imports: import pytest
  import numpy
  from numpy.testing import assert_, assert_equal, assert_array_equal, assert_almost_equal, assert_array_almost_equal, assert_raises, assert_raises_regex
  from numpy.lib._index_tricks_impl import mgrid, ogrid, ndenumerate, fill_diagonal, diag_indices, diag_indices_from, index_exp, ndindex, c_, r_, s_, ix_
label_desc: Use image node_id 6 for calling the TestConcatenator obj's underlying member method code with example usage: obj.test_0d() without return types