if (buf.length() == 0) {
            return false;
        }
        return buf.charAt(buf.length() - 1) == ' ';
    }

    private static boolean removeLastDuplication(final StringBuilder buf, final int size, final boolean isSpace,
            final Set<String> termCache) {
        final String target = rightString(buf, size);
        if (!termCache.contains(target)) {

            final StringBuilder buf = new StringBuilder(100);
            if (strings.length > 1) {
                for (int i = 0; i < strings.length - 1; i++) {
                    if (buf.length() != 0) {
                        buf.append('.');
                    }
                    buf.append(strings[i]);
                }
                filePrefix = buf.toString();

        final StringBuilder buf = new StringBuilder();
        buf.append("<list>");
        if (values != null && !values.isEmpty()) {
            for (final String value : values) {
                buf.append("<item>");
                buf.append(trimSpace(XmlUtil.escapeXml(value)));
                buf.append("</item>");
            }
        }
        buf.append("</list>");
        // TODO support other type

                final StringBuilder buf = new StringBuilder(100);
                buf.append(tokenUrl);
                if (StringUtil.isNotBlank(tokenReqParams)) {
                    if (tokenUrl.indexOf('?') >= 0) {
                        buf.append('&');
                    } else {
                        buf.append('?');
                    }
                    buf.append(tokenReqParams);
                }

        }

        buf.append(',').append('"').append(FieldNames.FIELDS).append("\":").append(convertJsonStrings(fields));
        buf.append(',').append('"').append(FieldNames.TAGS).append("\":").append(convertJsonStrings(tags));
        buf.append(',').append('"').append(FieldNames.ROLES).append("\":").append(convertJsonStrings(roles));

        final StringBuilder buf = new StringBuilder();
        buf.append("<list>");
        if (values != null && !values.isEmpty()) {
            for (final String value : values) {
                buf.append("<item>");
                buf.append(trimSpace(XmlUtil.escapeXml(value)));
                buf.append("</item>");
            }
        }
        buf.append("</list>");
        // TODO support other type

            throw new ExtractException(e);
        }
        return buf.toString();
    }

    /**
     * Appends attachment content to the buffer if it can be extracted.
     *
     * @param buf the buffer to append content to
     * @param bodyPart the body part containing the attachment
     */
    protected void appendAttachment(final StringBuilder buf, final BodyPart bodyPart) {

            } else if (LOC_ELEMENT.equals(qName)) {
                if (buf != null) {
                    sitemapUrl.setLoc(buf.toString().trim());
                    buf = null;
                }
            } else if (LASTMOD_ELEMENT.equals(qName)) {
                if (buf != null) {
                    sitemapUrl.setLastmod(buf.toString().trim());
                    buf = null;
                }

        final List<AnalyzeToken> tokens = new ArrayList<>();
        final StringBuilder buf = new StringBuilder(maxAnalyzedContentLength);
        for (final String t : text.split("\\s")) {
            buf.append(t).append(' ');
            if (buf.length() > maxAnalyzedContentLength) {
                try {
                    tokens.addAll(analyzer.analyze(buf.toString().trim(), field, lang));

                    for (final StringBuilder buf : bufList) {
                        buf.append(alphabets[j]);
                    }
                } else if (bufList.size() < getMaxReadingNum()) {
                    final List<StringBuilder> tmpBufList = deepCopyBufList(originBufList);
                    for (final StringBuilder buf : tmpBufList) {
                        buf.append(alphabets[j]);
                    }