ormal tokenization) or one of {'bert', 'distilbert'}
                            tokenization and preprocessing for use with
                            BERT/DistilBert text classification model.
    encoding (str):        character encoding to use. Auto-detected if None
    lang (str):            language.  Auto-detected if None.
    val_pct(float):        Onlyl used if train_test_names  has 1 and not 2 names
    random_state(int):      If integer is supplied, train/test split is reproducible.
            