How to create objects based on a list?

So I am trying to create a certain amount of spheres in a SceneKit scene based on the number of objects in a list. So I think I would put an addChild in a for loop, but how would I assign them all to the same type of model? Especially because sometimes the list will be empty, so the model would not need to show up at all.

How to create objects based on a list?
 
 
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