code: def test_get_dummies_object():
      df = pd.DataFrame(
          {
              "a": pd.Categorical([1, 2, 3, 4, 4, 3, 2, 1]),
              "b": list("abcdabcd"),
              "c": pd.Categorical(list("abcdabcd")),
          }
      )
      ddf = dd.from_pandas(df, 2)
  
      # Explicitly exclude object columns
      exp = pd.get_dummies(df, columns=["a", "c"])
      res = dd.get_dummies(ddf, columns=["a", "c"])
      assert_eq(res, exp)
      tm.assert_index_equal(res.columns, exp.columns)
  
      with pytest.raises(NotImplementedError):
          dd.get_dummies(ddf)
  
      with pytest.raises(NotImplementedError):
          dd.get_dummies(ddf.b)
  
      with pytest.raises(NotImplementedError):
          dd.get_dummies(ddf, columns=["b"])
  
imports: from __future__ import annotations
  import contextlib
  import warnings
  import numpy
  import pandas
  import pytest
  from packaging.version import parse
  import dask.dataframe
  from dask.dataframe._compat import PANDAS_VERSION, tm
  from dask.dataframe.reshape import _get_dummies_dtype_default
  from dask.dataframe.utils import assert_eq, make_meta
label_desc: Use image node_id 3 for calling a global function with example usage: test_get_dummies_object() without return types