.get(stream -> stream.filter(StringUtil::isNotBlank).map(s -> s.trim() + ":").toArray(n -> new String[n]));
        fileProtocols = split(fessConfig.getCrawlerFileProtocols(), ",")
                .get(stream -> stream.filter(StringUtil::isNotBlank).map(s -> s.trim() + ":").toArray(n -> new String[n]));

        loadProtocols("org.codelibs.fess.net.protocol");

     * comment: Supported file protocols for crawling.
     * @return The value of found property. (NotNull: if not found, exception but basically no way)
     */
    String getCrawlerFileProtocols();

    /**
     * Get the value for the key 'crawler.data.env.param.key.pattern'. <br>
     * The value is, e.g. ^FESS_ENV_.* <br>
     * comment: Pattern for environment variable keys in crawling data.