seq.addModule(WebDAVAuthenticationModule.MODULE_NAME);
try {
seq.init(request.getSession());
} catch (Exception e) {
IOException ioe = new IOException("Failed to authentication scheme.");
ioe.initCause(e);
throw ioe;
}
seq.nextAuthenticationModule();
request.getSession().setAttribute(Constants.AUTH_SENT, Boolean.TRUE);
request.getSession().setAttribute(Constants.AUTH_SESSION, seq);