     % (encoding, encoding),
            verbose=verbose,
        )
        x_train = TU.decode_by_line(x_train, encoding=encoding, verbose=verbose)
        x_test = TU.decode_by_line(x_test, encoding=encoding, verbose=verbose)

    # detect language
    if lang is None:
        lang = TU.detect_lang(x_train)
    check_unsupported_lang(lang, preprocess_mode)

    # return preprocessed the texts
    preproc_type = tpp.TEXT_PREPROCESSORS.get(preprocess_mode, None)
    if None:
        raise ValueError(&#34;un