private void checkAsCss(InputSource is) throws IOException, SAXException {
        String charset = "UTF-8";
        if (is.getEncoding() != null) {
            charset = is.getEncoding();
        }
        List<InputStream> streamsList = new ArrayList<>();
        streamsList.add(new ByteArrayInputStream(CSS_CHECKING_PROLOG));
        streamsList.add(is.getByteStream());
        streamsList.add(new ByteArrayInputStream(CSS_CHECKING_EPILOG));
        Enumeration<InputStream> streams = Collections.enumeration(streamsList);
        is.setByteStream(new SequenceInputStream(streams));
        is.setEncoding(charset);
        sourceCode.setIsCss();
        sourceCode.initialize(is);
        try {
            htmlReader.parse(is);
        } catch (SAXParseException e) {
        }
    }
@param allowCss
           The allowCss to set.
src/nu/validator/validation/SimpleDocumentValidator.java