docs: public static void forwardRequest(
          String target,
          Map<String, String[]> params,
          HttpServletRequest req,
          HttpServletResponse res)
      throws IOException, ServletException {
  
          // cast the request back to a flex request so the parameter map can be accessed
          CmsFlexRequest f_req = (CmsFlexRequest)req;
          // set the parameters
          f_req.setParameterMap(params);
          // check for links "into" OpenCms, these may need the webapp name to be removed
          String vfsPrefix = OpenCms.getStaticExportManager().getVfsPrefix();
          if (target.startsWith(vfsPrefix)) {
              // remove VFS prefix (will also work for empty vfs prefix in ROOT webapp case with proxy rules)
              target = target.substring(vfsPrefix.length());
              // append the servlet name
              target = OpenCms.getSystemInfo().getServletPath() + target;
          }
          // forward the request
          f_req.getRequestDispatcher(target).forward(f_req, res);
      }