code: def test_error_when_regression_is_true_and_target_is_binary(
      df_discretise,
  ):
      with pytest.raises(ValueError):
          transformer = DecisionTreeDiscretiser(regression=True)
          transformer.fit(
              df_discretise[["var_A", "var_B"]], df_discretise["target"]
          )
  
file_path: feature_engine/tests/test_discretisation/test_decision_tree_discretiser.py
imports: import numpy
  import pandas
  import pytest
  from sklearn.exceptions import NotFittedError
  from feature_engine.discretisation import DecisionTreeDiscretiser, EqualWidthDiscretiser
label_desc: Use image node_id 7 for calling a global function with example usage: test_error_when_regression_is_true_and_target_is_binary(df_discretise) without return types