code: function (runtime, modName, cfg) {
              modName = indexMapStr(modName);
  
              var mods = runtime.Env.mods,
                  mod = mods[modName];
  
              if (mod) {
                  return mod;
              }
  
              // 防止 cfg 里有 tag，构建 fullpath 需要
              mods[modName] = mod = new Loader.Module(S.mix({
                  name: modName,
                  runtime: runtime
              }, cfg));
  
              return mod;
          }
docs: create single module info
  @param runtime Module container, such as KISSY
  @param {String} modName to be created module name
  @param {Object} [cfg] module config
  @return {KISSY.Loader.Module}