def METHOD_NAME(self):
    """
    Test basic usage with headers and a "x" variable name.
    """
    df_test = combine_csv.CombineCSV(self.__basename, "remove_me_54.csv",
            "large_number", write_header=True, x_varname='y')
    self.assertTrue(df_test._ended)
    gold_df = pandas.read_csv("{}/combine_basic_x.csv".format(
        self.__goldpath))
    self.assertTrue(df_test._final_df.equals(gold_df),
        msg="Pandas dataframe is different from gold CSV for x variable usage.")