code: def test_unknown_category_transform_array():
      x2 = da.from_array(
          np.array([["a"], ["b"], ["c"], ["d"]]), chunks=2
      )
      enc = dask_ml.preprocessing.OneHotEncoder()
      enc.fit(dX)
  
      result = enc.transform(x2)
      match = r"Block contains previously unseen values \['d'\].*\n+.*Block info"
      with pytest.raises(ValueError, match=match):
          result.compute()
  
imports: import dask.array
  import dask.dataframe
  import numpy
  import packaging.version
  import pandas
  import pytest
  import scipy.sparse
  import sklearn.preprocessing
  import dask_ml.preprocessing
  from dask_ml._compat import DASK_2_20_0, PANDAS_VERSION
  from dask_ml.utils import assert_estimator_equal
label_desc: Use image node_id 10 for calling a global function with example usage: test_unknown_category_transform_array() without return types