code: def test_mandatory_init_parameters():
      with pytest.raises(TypeError):
          RelativeFeatures(reference=["var1"], func=["add"])
      with pytest.raises(TypeError):
          RelativeFeatures(variables=["var1"], func=["add"])
      with pytest.raises(TypeError):
          RelativeFeatures(variables=["var1"], reference=["var2"])
  
imports: import numpy
  import pandas
  import pytest
  from sklearn.pipeline import Pipeline
  from feature_engine.creation import RelativeFeatures
label_desc: Use image node_id 1 for calling a global function with example usage: test_mandatory_init_parameters() without return types