docs: @Override
      protected void doCommonFilter(PortletRequest request, PortletResponse response, FilterChain chain)
              throws IOException, PortletException {
  
          List<PortletFilter> filters = getFilters(request);
  
          if (filters == null || filters.size() == 0) {
              if (logger.isDebugEnabled()) {
                  logger.debug(request.getParameterMap() +
                          (filters == null ? " has no matching filters" : " has an empty filter list"));
              }
  
              PortletFilterUtils.doFilter(request, response, chain);
  
              return;
          }
  
          VirtualFilterChain vfc = new VirtualFilterChain(request, chain, filters);
          vfc.doCommonFilter(request, response);
      }