resolve() {
        if (this._state !== 0 /* AsyncIterableSourceState.Initial */) {
            return;
        }
        this._state = 1 /* AsyncIterableSourceState.DoneOK */;
        this._onStateChanged.fire();
    }
Calling `resolve()` will mark the result array as complete.

**NOTE** `resolve()` must be called, otherwise all consumers of this iterable will hang indefinitely, similar to a non-resolved promise.
**NOTE** If `resolve()` or `reject()` have already been called, this method has no effect.