code: def test_dataframe_raises(self):
      df = pd.DataFrame({"A": ["a", "a", "b"]}, dtype="category")
      dpp.LabelEncoder().fit(df)  # OK
  
      df["other"] = ["a", "b", "c"]
      with pytest.raises(ValueError):
          dpp.LabelEncoder().fit(df)
  
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 8 for calling the TestLabelEncoder obj's underlying member method code with example usage: obj.test_dataframe_raises() without return types