har_order: A character n-gram order.
        n_word_order: A word n-gram order.
        n_order: A sum of character and word n-gram order.
        beta: A parameter determining an importance of recall w.r.t. precision. If `beta=1`, their importance is equal.
        lowercase: An indication whether to enable case-insensitivity.
        whitespace: An indication whether to keep whitespaces during character n-gram extraction.

    Return:
        Return chrF/chrF++ score and statistics for the best matching hypothesis and reference.

        f_score: A sentence-level chrF/chrF++ score.
        matching_char_n_grams:
            A total number of matching character n-grams between the best matching reference and hypothesis.
        matching_word_n_grams:
            A total number of matching word n-grams between the best matching reference and hypothesis.
        target_char_n_grams: A total number of reference character n-grams.
        target_word_n_grams: A total number of reference word n-grams.

    r