code: def test_when_apply_shape_into_2d_then_returns_correct_shape():
      assert shape_into_2d(np.array(1)) == np.array([[1]])
      assert np.all(
          shape_into_2d(np.array([1, 2, 3, 4]))
          == np.array([[1], [2], [3], [4]])
      )
      assert np.all(
          shape_into_2d(np.array([[1], [2], [3], [4]]))
          == np.array([[1], [2], [3], [4]])
      )
      assert np.all(
          shape_into_2d(np.array([[1, 2], [1, 2], [1, 2], [1, 2]]))
          == np.array([[1, 2], [1, 2], [1, 2], [1, 2]])
      )
  
imports: import random
  import networkx
  import numpy
  import pandas
  import pytest
  from _pytest.python_api import approx
  from dowhy import gcm
  from dowhy.gcm.util.general import apply_catboost_encoding, apply_one_hot_encoding, auto_apply_encoders, auto_fit_encoders, fit_catboost_encoders, fit_one_hot_encoders, has_categorical, is_categorical, is_discrete, set_random_seed, setdiff2d, shape_into_2d
label_desc: Use image node_id 6 for calling a global function with example usage: test_when_apply_shape_into_2d_then_returns_correct_shape() without return types