code: def test_error_when_drop_original_not_bool():
      for drop_original in ["True", [True]]:
          with pytest.raises(ValueError):
              RelativeFeatures(
                  variables=["Age"],
                  reference=["Marks"],
                  func=["add", "mul"],
                  drop_original=drop_original,
              )
  
imports: import numpy
  import pandas
  import pytest
  from sklearn.pipeline import Pipeline
  from feature_engine.creation import RelativeFeatures
label_desc: Use image node_id 5 for calling a global function with example usage: test_error_when_drop_original_not_bool() without return types