code: def test_slice_columns():
      columns = [2, 3]
      df2 = slice_columns(df, columns)
      X2 = slice_columns(X, columns)
  
      assert list(df2.columns) == columns
      assert_eq_df(df[columns].compute(), df2.compute())
      assert_eq_ar(X.compute(), X2.compute())
  
imports: from collections import namedtuple
  import dask.array
  import dask.dataframe
  import numpy
  import pandas
  import pandas.testing
  import pytest
  from dask.array.utils import assert_eq
  from dask.dataframe.utils import assert_eq
  from dask_ml.datasets import make_classification
  from dask_ml.utils import _num_samples, assert_estimator_equal, check_array, check_chunks, check_matching_blocks, check_random_state, handle_zeros_in_scale, slice_columns
label_desc: Use image node_id 1 for calling a global function with example usage: test_slice_columns() without return types