def METHOD_NAME(self):
    """
    Test exception when bad "x" variable name is provided.
    """
    with self.assertRaises(combine_csv.CombineCSV.CombineError) as cerr:
        df_test = combine_csv.CombineCSV(self.__basename,
                "remove_me_54.csv", "large_number",
                x_varname='bad_x54_name')
    self.assertEqual(cerr.exception._name, "XVariableError")