reject(error) {
        if (this._state !== 0 /* AsyncIterableSourceState.Initial */) {
            return;
        }
        this._state = 2 /* AsyncIterableSourceState.DoneError */;
        this._error = error;
        this._onStateChanged.fire();
    }
Writing an error will permanently invalidate this iterable.
The current users will receive an error thrown, as will all future users.

**NOTE** If `resolve()` or `reject()` have already been called, this method has no effect.