code: def slice_columns(X, columns):
      if isinstance(X, dd.DataFrame):
          return X[list(X.columns) if columns is None else columns]
      else:
          return X
  
imports: import contextlib
  import datetime
  import functools
  import logging
  import warnings
  from collections.abc import Sequence
  from multiprocessing import cpu_count
  from numbers import Integral
  from timeit import default_timer
  import dask
  import dask.array
  import dask.dataframe
  import numpy
  import pandas
  import sklearn.utils.extmath
  import sklearn.utils.validation
  from dask import delayed
  from dask.array.utils import assert_eq
  from dask.dataframe.utils import assert_eq
  from ._utils import ConstantFunction
label_desc: Use image node_id 4 for calling a global function with example usage: slice_columns(X, columns) and returns: X, X