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Hi everyone, is there any suggestions to run task2 until task1 finished when they have no dependency?
```with Flow('feature-factory') as flow:
    a, b = pre_task()
    task1.map(a)
    task2.map(b) ```

It seems like an easy question. Currently my workaround solution for this is to add a meaningless dependency for them. Is there any better way to achieve this?

```with Flow('feature-factory') as flow:
    a, b = pre_task()
    state = task1.map(a)
    task2.map(b, state) ```


Think `upstream_tasks` kwarg is what you’re looking for

image.png

```b.map(task2, upstream_tasks=[task1.map(a)])```
I don’t know why task2 only run once (should be 9 runs), in my case, feature_generator=task1, dataset_generator=task2

And I find another workable solution
```a_task = task1.map(a)    a_task.set_downstream(task2.map(b))```


Hey <@U02AA2K81J4>,

I think you want something like
```a = A.map(...)
b = B.map(..., upstream_tasks=[a])```

If you want `a` to fully complete before `b` ,
```a = A.map(...)
b = B.map(..., upstream_tasks=[unmapped(a)])```
where `unmapped` is imported from Prefect.