How to use the sister.tokenizers.JapaneseTokenizer function in sister

def setUp(self):
        self.tokenizer = tokenizers.JapaneseTokenizer()

def __init__(
            self,
            lang: str = 'en',
            tokenizer: Tokenizer = None,
            word_embedder: WordEmbedding = None) -> None:
        tokenizer = tokenizer or {"en": SimpleTokenizer(),
                                  "fr": SimpleTokenizer(),
                                  "ja": JapaneseTokenizer()}[lang]
        word_embedder = word_embedder or FasttextEmbedding(lang)
        super().__init__(tokenizer, word_embedder)