Hello,

There is already a flow.until_flows() method in the library, which waits for the completion of a certain list of flow instances. But it's not comfortable to use it when the parallel flows are scattered in different functions, modules and components.

So I added the ability to specify a group_id option for flows, as well as the function flow.until_group(group_id). the most popular group_id in practice will be, hm... animations I think! 😄

I have also added examples of using flow.until_flows() and flow.until_group() to the flow.script file.

Cheers!