class ServletContainerImpl implements ServletContainer {

    @Override
    public Filter getFilterForClass(final Class<? extends Filter> filterClass, final FilterConfig filterConfig)
            throws FilterInitializationException, ServletException {
        if (filters.containsKey(filterClass)) {
            return filters.get(filterClass);
        }

        Filter filter = instantiateFilter(filterClass);
        filter.init(filterConfig);
        filters.put(filterClass, filter);
        return filter;
    }

    public  ServletContainerImpl(final DateProvider dateProvider,
                                final long servletTimeToLiveInMs,
                                final long monitoringIntervalInMs);

}