code: function(parentId, module, callback) {
      if (typeof module === "string") {
          var payload = lookup(parentId, module);
          if (payload != undefined) {
              callback && callback();
              return payload;
          }
      } else if (Object.prototype.toString.call(module) === "[object Array]") {
          var params = [];
          for (var i = 0, l = module.length; i < l; ++i) {
              var dep = lookup(parentId, module[i]);
              if (dep == undefined && require.original)
                  return;
              params.push(dep);
          }
          return callback && callback.apply(null, params) || true;
      }
  }
docs: Get at functionality define()ed using the function above