Support subset by collection of IDs

[GeekOnCoffee]

We want to be able to generate a subset for a specific set of ids and their relationships, not a random collection.

[evoxmusic]

It makes sense, it's what we call the Select Strategy that we need to implement. Today only the Random Strategy is available.

[bbstilson]

@evoxmusic Just curious if there has been any progress on this strategy? I might have some time to take a look at implementing it if it's still desired and unimplemented 🙂