code: function race(iterable) {
      var C = this;
      var capability = newPromiseCapability(C);
      var reject = capability.reject;
      var result = perform(function () {
        forOf(iterable, false, function (promise) {
          C.resolve(promise).then(capability.resolve, reject);
        });
      });
      if (result.e) reject(result.v);
      return capability.promise;
    }
docs: 25.4.4.4 Promise.race(iterable)