protected ExtractData createExtractData(final String content) {
        return new ExtractData(extractString(content));
    }

    /**
     * Detects the encoding of the input stream.
     * @param bis The buffered input stream.
     * @return The detected encoding.
     */
    protected String getEncoding(final BufferedInputStream bis) {
        final byte[] b = new byte[preloadSizeForCharset];
        try {