final Map<String, AnalysisProvider<TokenizerFactory>> extra = new HashMap<>();
        extra.put("reloadable_kuromoji_tokenizer", KuromojiTokenizerFactory::new);
        extra.put("reloadable_kuromoji", KuromojiTokenizerFactory::new);
        extra.put("ngram_synonym", NGramSynonymTokenizerFactory::new);
        return extra;
    }