public static boolean isServletRequestAuthenticatorInstanceOf(Class<? extends ServletRequestAuthenticator> clazz) {
        final AuthCheckFilter instance = getInstance();
        if (instance == null) {
            // We've not yet been instantiated
            return false;
        }
        return servletRequestAuthenticator != null && clazz.isAssignableFrom(servletRequestAuthenticator.getClass());
    }
Indicates if the currently-installed ServletRequestAuthenticator is an instance of a specific class.

@param clazz the class to check
@return {@code true} if the currently-installed ServletRequestAuthenticator is an instance of clazz, otherwise {@code false}.
xmppserver/src/main/java/org/jivesoftware/admin/AuthCheckFilter.java