code: def test_get_dummies_errors():
      with pytest.raises(NotImplementedError):
          # not Categorical
          s = pd.Series([1, 1, 1, 2, 2, 1, 3, 4])
          ds = dd.from_pandas(s, 2)
          dd.get_dummies(ds)
  
      # unknown categories
      df = pd.DataFrame({"x": list("abcbc"), "y": list("bcbcb")})
      ddf = dd.from_pandas(df, npartitions=2)
      ddf._meta = make_meta(
          {"x": "category", "y": "category"}, parent_meta=pd.DataFrame()
      )
  
      with pytest.raises(NotImplementedError):
          dd.get_dummies(ddf)
  
      with pytest.raises(NotImplementedError):
          dd.get_dummies(ddf, columns=["x", "y"])
  
      with pytest.raises(NotImplementedError):
          dd.get_dummies(ddf.x)
  
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 10 for calling a global function with example usage: test_get_dummies_errors() without return types