@Override
    public void startPrefixMapping(String arg0, String arg1)
            throws SAXException {
        if (ch != null) {
            ch.startPrefixMapping(arg0, arg1);
        } else {
            String[] arr = new String[2];
            arr[0] = arg0;
            arr[1] = arg1;
            namespaces.add(arr);
        }
    }
@see org.xml.sax.ContentHandler#startPrefixMapping(java.lang.String,
     java.lang.String)
src/nu/validator/servlet/BufferingRootNamespaceSniffer.java