code: def test_unseen_raises_array(self):
      enc = dpp.LabelEncoder().fit(y)
      new = da.from_array(np.array(["a", "a", "z"]), chunks=2)
      result = enc.transform(new)
  
      with pytest.raises(ValueError):
          result.compute()
  
imports: import dask
  import dask.array
  import dask.dataframe
  import numpy
  import pandas
  import pytest
  import sklearn.preprocessing
  from dask.array.utils import assert_eq
  import dask_ml.preprocessing
  from dask_ml.utils import assert_estimator_equal
label_desc: Use image node_id 10 for calling the TestLabelEncoder obj's underlying member method code with example usage: obj.test_unseen_raises_array() without return types