public void createDefaultChain(String chainName) {
        // only create the defaultChain if we don't have a chain with this name already
        // (the global filters will already be in that chain)
        if (!getChainNames().contains(chainName) && !CollectionUtils.isEmpty(globalFilterNames)) {
            // add each of global filters
            globalFilterNames.stream().forEach(filterName -> addToChain(chainName, filterName));
        }
    }
Sets the {@code FilterConfig} provided by the Servlet container at webapp startup.

@param filterConfig the {@code FilterConfig} provided by the Servlet container at webapp startup.
web/src/main/java/org/apache/shiro/web/filter/mgt/DefaultFilterChainManager.java