code: def test_standardize_all_columns_ndarray():
      ary = np.array([[0, 10], [0, 9], [0, 8], [0, 7], [0, 6], [0, 5]])
  
      ary_actu = standardize(ary, columns=None)
      ary_expc = np.array(
          [
              [0.0, 1.46385],
              [0.0, 0.87831],
              [0.0, 0.29277],
              [0.0, -0.29277],
              [0.0, -0.87831],
              [0.0, -1.46385],
          ]
      )
  
      np.testing.assert_allclose(ary_actu, ary_expc, rtol=1e-03)
  
file_path: mlxtend/mlxtend/preprocessing/tests/test__scaling__standardizing.py
imports: import numpy
  import pandas
  from mlxtend.preprocessing import standardize
label_desc: Use image node_id 8 for calling a global function with example usage: test_standardize_all_columns_ndarray() without return types