public Scrib_lua_mod Register(Scrib_core core, Io_url script_dir) {
   this.core = core;
   Init();
   mod =
       core.RegisterInterface(
           this,
           core.App()
               .Fsys_mgr()
               .Bin_xtns_dir()
               .GenSubFil_nest("ParserFunctions", "mw.ext.ParserFunctions.lua"));
   return mod;
 }