code: function unshift(...next) {
      return function (it) {
          return __asyncGenerator(this, arguments, function* () {
              for (let i = 0; i < next.length; ++i)
                  yield yield __await(next[next.length - i - 1]);
              yield __await(yield* __asyncDelegator(__asyncValues(it)));
          });
      };
  }
docs: Prepend an item to the beginning of an iterable