docs: function lightNg(moduleName) {
          if (!moduleName) {
               throw 'lightNg moduleName Required';
          }
  
          var module = Modules[moduleName];
  
          if (module) {
              //return existing module
              return module;
          } else {
              //create new module
              module = new lightNgModuleConstructor();
              Modules[moduleName] = module;
              return module;
          }
      }