code: def test_error_when_required_params_not_entered():
      with pytest.raises(TypeError):
          MathFeatures(func=["mean", "sum"])
      with pytest.raises(TypeError):
          MathFeatures(variables=["vara", "varb"])
  
imports: import numpy
  import pandas
  import pytest
  from sklearn.pipeline import Pipeline
  from feature_engine.creation import MathFeatures
label_desc: Use image node_id 1 for calling a global function with example usage: test_error_when_required_params_not_entered() without return types