code: def check_error_param_missing_values(estimator):
      """
      Only for transformers with a parameter `missing_values`in init.
  
      Checks transformer raises error when user enters non-permitted value to the
      parameter.
      """
      # param takes values "raise" or "ignore"
      estimator = clone(estimator)
      for value in [2, "hola", False]:
          if estimator.__class__.__name__ == "MathFeatures":
              with pytest.raises(ValueError):
                  estimator.__class__(
                      variables=["var_1", "var_2", "var_3"],
                      func="mean",
                      missing_values=value,
                  )
  
          elif estimator.__class__.__name__ == "RelativeFeatures":
              with pytest.raises(ValueError):
                  estimator.__class__(
                      variables=["var_1", "var_2", "var_3"],
                      reference=["var_4"],
                      func="mean",
                      missing_values=value,
                  )
          else:
              with pytest.raises(ValueError):
                  estimator.__class__(missing_values=value)
  
label_desc: Use image node_id 1 for calling a global function with example usage: check_error_param_missing_values(estimator) without return types