@SuppressWarnings("unchecked")
    private void addLegacyFilterChain(String pattern, FilterConfigKey filterConfigKey) {
        FilterConfig<Filter> filterConfig = new FilterConfig<>(filterConfigKey.getKey(), filterConfigKey.getConfigValue());
        addFilterChain(pattern, filterConfig);
    }
Filter configuration which pairs a Filter class with its configuration used on a path.

@param <T> The Servlet Filter class.
@since 1.4
support/guice/src/main/java/org/apache/shiro/guice/web/ShiroWebModule.java